Red: Nerf
Green: Buff
Tan: Neither Buff nor Nerf (to dev's knowledge)
Blue: Overhauled Change
Pink: Planned Change
White: Unchanged

Credit to the HDR Development Team for certain bits and pieces of code and other assets for usage in this modpack
(https://github.com/HDR-Development)

Credit to WuBoytH for status script edits and code
(https://github.com/WuBoytH)

Credit to Chrispo for making a bunch of these mechanics
(https://gamebanana.com/members/1762815)

Wavedashing/Wavelanding:

A physics engine exploit (in Super Smash Bros Melee), or technique in Super Smash Bros Ultimate, which is performed by airdodging diagonally into the ground. Doing this will cause the character to slide some distance, which depends on your traction. The difference between these techniques has to do with distance between air and ground.

Edge Canceling:

A technique present in all Smash games where hitting the ledge or end of a platform during a move will cancel any endlag the move would normally have.

B Reversing:

A technique first introduced in Super Smash Bros Brawl, where you can reverse the facing direction and momentum of a move (namely a special) by flicking the control stick in the opposite direction during the first 4 frames of the move.

Fallout Fixing:

Usually means a move was given sufficient knockback to make the opponent move more consistently towards the center of the move, or it was given an autolink angle (367), which tries to pull opponents towards the center of the hitbox. If it's not specifically this setup, clarification will be given.

Land Canceling:

A technique mainly present in Super Smash Bros Melee, where certain moves have all their landing lag canceled if they landed during the move.

Hitfall/Hitfalling:

A technique that debuted in Rivals of Aether, where you can fast fall during the hitlag of a move.

Hitflow:

Whenever you hit the opponent (excluding hits on shield), the rest of the animation will be sped up by a listed multiplier until the end of the move. An example is Lucario's Down Tilt, who's Down Tilt goes from Frame 7 and a Cancel Frame of 20, to Frame 4 and a Cancel Frame of 12.

KO Percent is based on Mario with no DI/ASDI (clarified later on) from the Center of FD or the Ledge of FD

Windows are measured in frames

Jumpsquat is now univerally 4 frames (excluding Kazuya)

Platform Dropping is enabled during the following statuses:

Initial Dashes, Running, Turns, Dash Turns, Ledge Teetering, Crouches, Airdodge Landing Lag, Item Grabs, Item Tosses, and Shield.
(Holding Special during Airdodge Landing Lag and Item Pickups disables platform dropping)

Maximum Directional Airdodge Landing Lag: 20 -> 10

Perfect Wavedashing can be done by holding down the airdodge button during jumpsquat

Maximum Length Wavedashes can be performed by holding the control stick horizontally

Crouching can be performed out of initial dash and run.

During most statuses, whenever you jump from the ground to the air, your momentum will be preserved, so for instance, if Captain Falcon jumps from a run, he will continue to move at the same speed in the air as he did on the ground.

In relation to this, all the following params have been adjusted:

Ground to Air Horizontal Momentum Multiplier: Original Value -> 1.0
Maximum Initial Horizontal Air Speed from Grounded Jump: Original Value -> 3.0
Maximum Horizontal Velocity from Jump: Original Value -> 3.0
Maximum Initial Horizontal Air Speed from Aerial Jump: Original Value -> 3.0

These values are the case for most fighters, but will be adjusted depending on a fighter by fighter case.

While you are airborne and actionable (Or landing an aerial or special), you can double tap the control stick in the opposite direction you’re facing to switch direction.
(This is only doable once per airtime.)

tl:du

Slightly nerfs how fast aerials can come out, and makes wavedashing more lenient
Wavedashing is now a useful, yet (hopefully) not overcentralizing tool
Platforms are significantly less "sticky"
Significantly increases micromanagement of movement
Lessens the limitations of combo extension by essentially not limiting how fast a character can move from ground to air
Permits new combo sequences and makes certain recoveries easier

Windows are measured in frames

Shielding can now be performed out of an initial dash

Shield Max HP: 50 -> 20

Minimum Shield Scale: 0.15 -> 1 (Removes Shield Poking)

Minimum Shield Hold Frames to Drop Shield: 3 -> 0

Shield HP Degeneration per Frame: 0.15 -> 0.0

Shield HP Regeneration per Frame: 0.08 -> 0.0277

Extra Shield Damage: 1.19 ->  1
Parry Activation Window from Shield Drop (Measured in Frames): 3 -> 1
Parry Pushback Multiplier: 0.15 -> 0.0
Shield Break HP: 37.5 -> 5.0

Shield Breaking has been overhauled:

There are now two variants of shield breaks, being soft shield breaks, and hard shield breaks. Soft Shield Breaks are performed by reducing a shields HP to 0, which forces the defender to enter a dizzy animation that makes them inactionable for 33 frames.

Hard Shield Breaks are performed by doing 30% (Normal Damage + Shield Damage) or more to a shield in a single attack. Doing so inflicts special zoom, and makes the defender inactionable for 192 frames, then forces them into a tech chase scenario. The required damage to force a hard shield break decreases the less health a shield has, going down to a minimum of 15% required to break it.

Parrying has been overhauled:

Upon parrying an attack, it will force the opponent into a recoil animation, akin to Sora's Counterattack. Said parry provides 35 frames of advantage for the defender.  

Maximum Parry Count: 6 -> 999

Dodges now have standardized intangibility and First Actionable Frame:

Dodge Intangibility Duration: 2-15 (Spotdodge), 4-18 (Forward Roll/Back Roll)
Dodge First Actionable Frame: 29 (Spotdodge), 38 (Forward Roll/Back Roll)

Dodge Staling Removed

Spotdodge Canceling Removed
Dodge Canceled Item Throw Frame: 2 -> 5

Canceling a Dodge into an Item Throw will enable a Glide Toss.

Glide Tossing effectively transfers the momentum you’d normally move during the roll into sliding actionable momentum.

Airdodges now have standardized intangibility and First Actionable Frame:

Airdodge Intangibility Duration: 3-22 (Neutral), 3-33 (Directional)
Airdodge First Actionable Frame: 45 (Neutral), 55 (Directional)

Airdodge Staling Removed

Airdodge Sling Removed: (Direction Airdodge Pullback Distance: 7 -> 1, Direction Airdodge Pullback Duration: 4 -> 0)

Airdodges can now be canceled into a Zair from frames 1-5.

Airdodges can now be canceled into an item throw from frames 1-5.

Doing so enables an aerial glide toss, functioning similar to a grounded glide toss.

Directional Airdodge Momentum has been completely overhauled:

Instead of falling and controlling your drift, you move a short distance, before freezing in place. The freeze starts on frame 25, and ends on frame 47, after which you'll fall straight down and can begin drifting again.

Maximum DI Angle: 9.74 -> 12

SDI has been completely removed, being replaced with HDR.

HDR stands for Hitstop Directional Repositioning, which means that for every infliction of hitstop you take, you get teleported a certain distance in the direction you’re holding in. The multiplier is 2.15, and is measured in the smallest training mode units.

Attack Hitstun Cancel Frame: 45 -> 999

Airdodge Hitstun Cancel Frame: 40 -> 999

Tumble can now be fast fallen

Removed the homogenization of gravity and fall speed during hitstun from knockback that launches at 70-110 degrees

Mashing has been overhauled significantly:

For every status excluding Bury and Frozen, mashing has been removed entirely, but to compensate, the base timer has been decreased significantly, and the scaling of mashing based on damage is decreased:

(Internally, the amount of time that an input decreases the remaining time in the status is known as clatter)

Arcade Bunny Crane:

Base Grab Time: 140 -> 70
Clatter: 3 -> 0

Boss Galaga:

Base Grab Time: 110 -> 60
Damage Time Scaling: 7 -> 3
Clatter: 8 -> 0

Beetle:

Base Grab Time: 100 -> 40
Damage Time Scaling: 3.4 -> 2.0
Status Decrement: 0 -> 1
Clatter: 8 -> 0

Bury:

Clatter: 8 -> 0

Cargo:

Additional Clatter: 50 -> 0
Clatter Multiplier: 1.5 -> 0

Chokehold:

Max Grab Time: 100 -> 999
Clatter: 4 -> 0
Damage Time Scaling: 1.5 -> 1.0
Clatter Upper Limit: 30 -> 0
Clatter Lower Limit: 10 -> 0

Chomp:

Base Grab Time: 120 -> 30
Damage Time Scaling: 0.5 -> 0.3
Clatter: 10 -> 0

Disable:

Clatter: 8 -> 0

Fish:

Base Grab Time: 90 -> 40
Damage Time Scaling: 1.7 -> 1.4
Clatter: 8 -> 0

Flower:

Base Flower Time: 140 -> 45
Time Scaling: 40 -> 5
Maximum Flower Time: 3000 -> 300
Clatter: 16 -> 0

Frozen:

Clatter: 4 -> 0

Grab:

Base Grab Time: 90 -> 30
Time Scaling: 1.7 -> 1.15
Clatter: 8 -> 0

Monkey Flip:

Base Grab Time: 70 -> 30
Time Scaling: 1.3 -> 1.05
Clatter: 6 -> 0

Nosferatu:

Base Grab Time: 80 -> 40
Clatter: 1.5 -> 0

Pin:

Base Grab Time: 160 -> 60
Damage Time Scaling: 2.0 -> 1.1
Clatter: 20 -> 0

Shield Break:

Base Time: 400 -> 121
Clatter: 3 -> 0

Sleep:

Handicap Time Scaling: 30 -> 20
Knockback Time Scaling: 25 -> 18
Clatter: 8 -> 0

Space Pirate Rush:

Base Grab Time: 75 -> 40
Damage Time Scaling: 1.36 -> 1.05
Clatter: 2 -> 0

Star:

Clatter: 1 -> 0

Stun:

Base Stun Time: 76 -> 30
Clatter: 5 -> 0

Yuri Kozukata:

Clatter: 1 -> 0

During the Bury and Frozen states, holding down the attack or special button will now automatically mash out of the status. It mashes at an approximate rate of 12 times per second.

Crouch Cancel Knockback Reduction Multiplier: 0.85 -> 0.67

Crouch Canceling a move that doesn't send you into tumble will reduce the current hitstun by half

Bury now gives 33% knockback resistance

Footstools are now untechable

tl:du

Buffs shielding in certain areas, and nerfs them in others
Makes shield breaks more common, and standardizes their length
Makes parrying significantly stronger
Standardizes Dodges
Allows for tricky item movement
Makes directional airdodges better for recovery but worse for juggling
Enables more defender interaction in combos, and reduces hand strain
Makes fast fallers more susceptible to combos, but better against vertical KO's
Lessens the hand strain on relatively common statuses, and generally speeds up said statuses
Makes Crouch Canceling a useful option
Incentivizes staying in Buried to weaken attacker moves
Makes footstool combos more effective