What is Weight Rate?
Weight Rate (WR from now) is an old feature inherited from Dark Souls 1, that has no real use in vanilla Elden Ring (it is set to 0 for all weapons in vanilla ER). Basically, it adds additional frames windows to animations recoveries when cancelling into another one, hence the higher the Weight Rate, the more time it takes to chain actions, and the more slower it feels and performs. This is mostly used with attacks animations, but It doesn´t restrict to attacks only though, WR can be also applied to several different actions, like dodging, using objects, Ashes of War, etc.
This mod reactivates WR and adds uniquessness to all weapons, so each one has a different WR inside the same weapon category. This means two different weapons from the same category will perform differently, acttacks chains speed wise. WR in this mod is proportionally adjusted in relation with Weapon Weight parameter. The higher the Weapon Weight, the more the WR, and the slower the weapon will be.
WR goes from 0 (minimum) to 1 (maximum) and acts as a multiplier for the additional cancel frames window. So, a WR = 0 will negate any additional cancel frames window and the following action will be performed instantly (when allowed), and a WR = 1 will add all the frames of the additional frames cancel window and the following action will be delayed. Additional cancel frames windows depends on weapons categories. Lighter weapons categories have smaller frames cancel windows, and vice versa. For example, Daggers category has a 3 frames additional cancel window, whilst Colossal Swords has a 9 frames one.
Lets see an example:
Category: Daggers
Additional cancel windows frames for this weapon category: 3 frames
Weapon: Cinquedea
Weight Rate: 0.87
Additional cancel windows frames for this weapon: 3 frames X 0.87 = 2.61 frames
Weapon: Glintstone Kriss
Weight Rate: 0.39
Additional cancel windows frames for this weapon: 3 frames X 0.39 = 1.06 frames
In this example, you can see the Cinquedea chains attacks and other actions one frame and a half slower than the Glintstone Kriss (2.6 frames vs 1 frame). Each weapon inside it category has it own unique WR, so no two weapons perform exactly the same (with a few exceptions).
Weight Rate and Physical Affinities
Physical affinities (Heavy, Quality, Keen, Occult) in this mod not only affect damage output, they also affect several performance parameters, like Guard Boost, Guard Repel, Physical Absortion, Stamina Consumption, and of course Weight and consequently Weight Rate. This way you can change how a weapon performs, speed wise, depending on the Affinity you insert into it. More info in Affinities section.