Concealment allows a greater diversity of characters and a greater "Noir genre" atmosphere.

• "Can be concealed ?" columns in the weapons charts

• "xxxx can be successfully concealed without a Check." in some cyberware weapon, popup weapon and other

• Conceal / Reveal skill

All these points lead us to one main idea, Concealment is a thing in Cyberpunk RED.

Facts

Well, Handgun is the skill that give you access to most of the concealed weapons for 2 reasons :

• Medium and Heavy pistol + SMG can be concealed

• Most of Handgun are onehanded, and onehanded weapon can be concealed without a check in a Popup Ranged Weapon

• You can upgrade a non-concealable onehanded weapon the ability to be concealed. (VH pistol, HSMG, Kendachi dragon)

"Most" is the important part here

• Shoulder arms have a Popup Shotgun (2 ammos)

• Heavy weapons  have

  • • Popup Grenade launcher (2 ammos)

    • Kendachi dragon flamethrower is one handed meaning you can put it in a Popup Ranged Weapon cyberarm option (2 ammos)

    • Towa Pocket Launcher can be concealed WHEN unloaded.

I may have missed some of them.

Conlcusion

That's why it's important, you make a choice : Big Damage or Short range medium damage, but always on you.

Well, that another story, another balance.

• Martial arts : best damage dealing skill in the game, perfectly concealable ? (well... you are using a linear frame), always on you

• Brawling :  Can be effective with Disarm & Choke actions, perfectly concealable as you don't need a Linear Frame

• Melee : all type of Melee weapon can be concealed. But that might cost a lot of money to conceal a Kendachi Mono Three.

In these case, you will deal damage, high level damage, with a concealable weapon : either with a Cybersnake, a Wolvers, a Popup Melee Weapon, or a Fūma Kotarō Linear Frame. (there are some other choice, I'm not gonna list them here) the tradeoff --> it's close combat only in CPR. (CEMK have an exception)

Well the rule aren't clear here. But we have a answer here : "City council 52:13 Concealing Armor"

LAJ and more are visible, Kevlar is concealable but can be detected.

Fortunately we have the Mimic Clothing Kit from Blackchrome  which can turn a Jacket from any fashion into a LAJ. And we have some other stuff there to be fashion, protected and conceal.

The Subdermal Armor is also a great choice here, infiltrators PCs in my group love it.

Executive a Corporate Threat rating are definitely places where Cops are around, NCPD Lawmen, Corpo cops, Security services, whatever. They are here and they don't want this peaceful area to turn Combat Zone. They are going to sniff around any people that might be a threat to the corporate peace they are paid to protect.  

Places like nightclub, bar, venues, can be very protective, they will refuse people with weapons, any weapons. Some of them can be concealed and you might get through security services with them. Other can't be concealed and you can forget bringing them inside. That's why some Fixers, or corporate Executive like to meet with dangerous people like Edgerunners in these kind of places.

Peoples, some of them, even in the worst area of NC, naming the Combat Zones, might not tolerate heavy weaponry when meeting with Edgerunners for a deal. Of course they aren't gonna even try to strip you from all your weapons, but big guns might not be allowed to the party. After all, if you are here in good faith for negotiate something, you don't need all your big firepower.

Carryall, yes... you can use one of those to conceal a Unconcealable weapon, because a weapon is Concealable under your clothes or not Concealable under your clothes. NCPD will check it if your look suspicious in a place where they don't want any trouble.

That's quite an important skill if you don't want to use cyberware. 

Cyberweapons, Popup weapons and Hidden Holster are all excellent solution to skip this skill IF you only want to Conceal weapons. But it's still a very good skill for investigation and you never know when you will want to conceal something while not having a Subdermal Pocket installed.

The concealable trait is an important part of the game. You shouldn't overlooked it. And be careful with TechUp that will allows your PC to bring their big guns everywhere, that will change the atmosphere and the balance in your combat. Think about it twice. Does it fit your campaign ? If yes, go for it of course. 

By keeping the balance, you will have more diverse characters at your table and they will have to make more choices. That's variety for you as a GM.