What I want to do works for me in 5e. Perhaps I didn't explain it clearly or well enough, but I would basically want to replicate my DM style from 5e to PF2 as much as possible. In 5e there is a large range (in CR/lvl) that the PCs can handle if not out right defeat. Enough so that I generally don't have to worry to much about telegraphing the scene other than my general description that I develop from a world building perspective. I don't have to think of extra telegraphing that it is a dangerous fight, I can just describe the effects of dragon passing through or whatever. Now that may be enough, but the range generally appears so narrow that my basic assumptions and descriptions from 5e wouldn't cut.Well, to be honest, I don't think that works in any game, let alone any incarnation of D&D; if you don't have any idea whether something is too dangerous for the PCs, you can't convey that to them, and if you don't, they're always potentially walking into a deathtrap. I don't really think that's not true with 5e either; I suspect you've just got internalized when its true there rather than doing it by calculation (which is probably a good thing since I gather the 5e encounter building guidelines are kind of junk).
Then of course I have a rather heavy use of random monster tables that complicates things even more. I think I would have to completely rework my existing tables to make it work for PF2. Not the end of the world, but still a fair bit of work.