I'd like to run this game on my MiSTer FPGA. It typically isn't listed under approved/banned emulators since it is hardware emulation and not software emulation. Would it be accepted on this board? Thanks.

It looks like MiSTer seems to be quite accurate, as FPGA is effectively hardware emulation.
As i don't have one to do any tests I'd say just submit your runs with the information that you used a MiSTer in the description.
I will check the footage then to verify the accuracy, if it's accurate I'll approve it and will add it to the rules.