I print ASA all the time on my Prusa MK3S. It's the filament I use the most. The printer is not encased, though it's also not in a draughty environment.
I rarely have a warped part, and I've printed from tiny parts to some that would take most of the bed and 10-30cm tall.
Keeping the bed clean is usually enough. For trickier parts I add a brim. I always use a release agent (I prefer a thin layer of talcum powder but glue and others work as well), otherwise it sticks badly and I've damaged more than a couple PEI sheets trying to get them off.
