Every modifier and layer key is oneshot for me, unless I use MagicCombo.
On one of my keyboards, I have a few gaming layers, each tweaked for a different game. I also have a prose layer and a programming layer. So if I want to play a game for which I have a layer for, I switch to the “game select” layer, and bounce from there to the final layer. Then, I have a non-game layer selector, to switch between prose (dvorak), programming (~programmer dvorak) and qwerty (so my wife can use the same keyboard too). My base layer has a single layer key, to switch to a hungarian symbols + numpad layer. I access the stepper layers via magic combos.
This is on my Raise, which I mainly use for gaming, but have the other layers because why not.
My daily driver is - of course - a Model01, for which my sketch is here: