@paradadf Thank you for the link, it explains a lot.
Unfortunately, this looks like both a huge disappointment and a distaster in the making.
First, the backporting of the fixes seems to mostly not work on the roms from the 0.78 romset, according to several messages in the thread you'll need to get the rom corresponding to the mame version of the backported fix..
And this can be any Mame version between 0.78 and 0.161 apparently without any documentation about which one to find.
Much worse and frankly worrying, again according to some message in the thread, it seems that they didn't even bother to test the old romset to see if it was still working, there is an explicit message about the backporting on one Sega System previously which broke ALL Sega systems... and this is just eight days ago.
So we get a new mame 0.78 for which backported fixes won't work unless you find for each backported fix the right rom inside a decade of mame evolution and whose original roms have no guarantee of working anymore ....