@VD-15 you can get multiple instances running simultaneously. You should set your thermal throttling to kick in at 80c and ensure proper ventilation to your cards.

I have been running 2 instances of a1111, if you provide the envvar CUDA_LAUNCH_BLOCKING=1, 2, etc. (zero indexed, zero is default) it will select the first available CUDA processor starting at the given device ID. So I just have a webui-user2.bat that has set CUDA_LAUNCH_BLOCKING=1

this isn't a perfect solution because some files cannot be read by both instances simultaneously on windows or something, but if this were linux I could run multiple installs off an overlaid models directory with a bind mount or symlink