One system is a Mac LC II with 10 megabytes. Even just trying to let it run the default startup startup scripts will result in a wedge, and I have never succeeded in getting to the kernel debugger on it.Looks the similar problem with PR/56932 on 12MB x68k: https://gnats.netbsd.org/56932
The 10 meg LC II still has issues, but I don't think this is due to this bug.
My LC III+ running 9.99.99 with this fix has been compiling non-stop for nine days and compiled perl in 7 days, 5 hours and 30 minutes, with no issues. Until this fix any non-trivial compile would lock it up.
Thanks! John