In the SU 12 beta, perhaps there no longer is a way to force safe mode. I’m using the beta and if I kill a running MSFS in Task Manager or if I kill MSFS with Alt F4 , then a file called running.lock is NOT created anywhere. And rebooting MSFS will not show the Safe option.
Before SU 12 beta, the method above would force MSFS into the Safe option the next time you booted MSFS. But no longer does this work.
I did a file search and no file named running.lock is located anywhere on my computer after killing MSFS in task manager or with Alt F4.