Bixby is the one yeah. Until AI assistants can ask clarifying questions and replicate arbitrary actions, they'll just get in my way.

As for the method, I use bxActions to remap buttons. You can add an action for a single press, a double press, a long press, and a double press and hold, and then a different set of actions on the lockscreen too.

Single press does indeed get pressed accidentally sometimes, so I have that as Media play/pause. Flashlight gets put on long press, which has extra functionality; if you release as soon as it comes on, it's a toggle, but if you keep holding the button it will turn off when you release it. Very convenient. The double press and double hold set screen rotation, although I don't use then very often. Double press on the lockscreen opens the camera.

You can add lots of other actions too, like an extra bright flashlight (both flashlights automatically turn off after 5 minutes), launch apps, switch apps, take a screenshot, use google assistant instead, set sound setting (like do not disturb, or IOS mode), other media buttons, volume buttons, home button, back button, open some system utilities, change one handed mode, toggle the screen (like pressing the power button), toggle fullscreen, and do some notification managment. Oh, and did I mention you can rebind the volume buttons too? That's 24 different actions you can bind.

Only issue I've had is it's not a system service, so android likes to kill it when it gets low on battery or RAM. But that's a problem for every custom service.

TL;DR: Both. Flashlight gets a 5 minute timer, and I also have it on a long press.