It seems like it only requires changes to segas18.cpp https://git.redump.net/hbmame/diff/src/hbmame/drivers/segas18.cpp?id=723738d56e87a9c448e492dec4baf3bba0540338
Just discovered this version today and it is very good thank you.
Can you add support for Clockwork Aquario? Apparently it is supported in some other versions of mame but I prefer your no nag version.