Perk Design
Solidarity recently received a buff to its numbers, due to being fairly situational in how often you actually get to use it. while this has definitely made the perk more useful, I wonder aloud if it's the right direction to take perk balance. Based off of BHVR's past balance actions, I think their ideal game state has all perks seeing some amount of use. I don't think they are afraid of some perks being more powerful than others or a meta forming, so long as their are no offensively powerful perks and the meta can be shaken up from time to time. With Solidarity as my reference point, I think there is another route to take it; instead of making the perk very powerful situationally and have no use otherwise, make it weak out of situation and powerful in situation, i.e, instead of buffing it from 50 to 70, keep it at 50 and give the rider: While uninjured, altruistic healing speed is increased by 10%. That way, the perk becomes more usable and fits well within builds it would be paired with anyways. This could also be useful for perks where if you are just unlucky in situation, you don't get to use it, like deliverance or unbreakable (albeit, I don't think these need buffs), or endgame oriented perks like left behind and no one left behind (hold on-).
this also leaves room for another area of design space I would like to see explored, being keywords. Exhausted already acts as an in game keyword and I think it makes balance surrounding them really interesting and a great move by the devs. It would be most helpful with preventing overstacking bonuses. To take my solidarity example, let's make that rider into a keyword called triage. If you stacked solidarity and botany knowledge, you'd be healing at 60% bonus speed. a little too good. but make bk's base healing bonus 40% and give it triage, now you heal at bonus 50% speed while uninjured and 40% bonus speed while injured whether running botany knowledge alone or botany knowledge with solidarity. It'd be a nice way to give little boosts to perks that need it without worrying too hard about how perks interact.
I also think there's room for backfill on this front; the gen powered perks (flashbang, wiretap, blast mine, chemical trap) could be codified to use gen progress as a resource to draw from rather than progressing simultaneously. leadership-type bonuses could be codified for future implementation with low risk of it being unbalanced
As for the benefits of this design philosophy, because it is probably equally balanced to the current one, it would allow more perks to see use in common rotation creating a more diverse perkscape, and it would enable the use of perks like left behind that are just not worth the slot. It could also be used to tone down some more frustrating perks that are technically balanced without nerfing them into the ground.
TL;DR I think it would be neat if BHVR started balancing situational perks away from being really strong situationally and towards being strong situationally and weak out of situation. They could do this using small, generalized bonus effects unified as keywords that prevented them from being stacked to the point of being unfun to play against for an overall more fun experience for both sides