First off the rom used in Mame plus is not the orginal rom that was dumped ( Correct one is in the first post of this thread ) It is a patched one . From what I can see is that they have patched the rom again to fix the GFX problems . I am not sure there is code to be used .
mameplus is using the same rom as listed in this post
"hs2a.03d", 0x000000, 0x80000, CRC(0153d371)
"hs2a.04d", 0x080000, 0x80000, CRC(0276b78a)
The changelog "fixed hsf2ad gfx" was only a fix for the rom name from "hsf2aj" to "hsf2ad".
You can verify this romset in mamplus. :>