@nil @moira many thanks for looking into this. I won't be able to try it soon, but when I do and run into this, I'll be sure to reach out!! You seem to be using the program for the SunPCi III whereas I have a SunPCi II. Possibly they are different. I still had the Ultra 5 on my desk in 2010-2011, so possibly the check isn't in that version or I indeed didn't boot up the card after 2009.
There is relatively little point in emulating that card btw. (A 2nd QEMU x86 instance will help more.)