Justice and Rule
Legend
What WWN does is assume that PCs start combat at full health and provide another means of implementing attrition. Your post-combat healing is just determining what the cost in System Strain you need to pay is. My homebrew system does something similar with stress, though it also implements stress more pervasively in the system (e.g., you can gain stress to cast spells even when you are out of mp or gain stress to save versus a consequence or take the successful option when making a saving throw).
Sure, and that's what I'm talking about. It doesn't really prevent you from healing up before every encounter, but what happens with strain is that it forces the players to make a choice about how much to continue on, and puts a good limit on continuous adventuring. As a mechanic it's a great way to force players into downtime naturally, rather than creating artificial breaks. It also creates a whole new vector for new mechanics, like making wilderness camping recover strain slower compared to staying in proper accomadations, among other things. It's just a very good idea that encourages players to make interesting attrition decisions instead of trying to artficially limit them from taking the "We heal up to full before proceeding" option every time.
Pathfinder 2e has a problem of being afraid to diverge from the traditional play loop even though it provides tools in the GMG to do so effectively. The VP subsystem should have been core. It would have made the value of these things immediately apparent. In that case, trying to make a Group Impression would be aclockVP subsystem, and so would the scenarios @!DWolf outlines in his response. The benefit of the skill feat becomes immediately obvious: you skip the clock and do it in one check. I think it would have also obviated the need to specify all the degrees of success for every skill action and would have allowed for more flexibility in using skills. The normal would be clocks, and skill feats allow you to short circuit that.
I think part of the problem is that, in creating a system that covers a lot of areas for Society play, people don't make decisions that better fit their own table. Like, Make an Impression is fine as a set of guidelines that you can modify to fit your situations as needed. The VP systems are definitely good for most things, but they outright say in a lot of the more free-form parts of play like Diplomacy, Downtime, and Exploration, you are explicitly told to try and modify things to fit the desires of your players, what they provide are largely meant as guidelines to give you an idea of how things function and how they designed things.
I do think that things may have been better to be more open in how things are run and provide a book of "hard rules and answers" for PFS, but I also get that doing such a thing would be a hassle and that it's easier to design for store play outright and just let GMs go off on their own.
And yeah, I feel like a lot of the complaints about "This feat means you can only do this if you have the feat!" miss that those feats are really more about "I can skip the rigamarole and just go for it" instead of having to make multiple checks. The Dandy feat that allows one to create a rumor on a single roll fits this exactly, where creating a rumor would take multiple checks to do it successfully, but having the feat allows you to save time by just hitting it with one.