Alright, so far the biggest issue that I have with TAStudio regarding MAMEHawk is Savestates dont always load correctly. They arent always loading the same inputs from previous frames. I had to sometimes delete them by clearing green zones so incorrect data wasnt loaded. This might not be an issue with the core itself but possibly a leftover with the same bug in 2.3.3, but I am not certian. However it's clear that this bug is really bad with this core as of now.
There is also a weird static noise that plays when you start up Splatterhouse, This does not happen in MAME-rr when I tested it, I have not tested it with the more recent MAME versions yet.
Trying to load movie via File->Movie->Play Movie will make BizHawk freeze entirely and you cant close out of it. most likely not supported yet (was trying to do this to see what the refresh rate of Splatterhouse is). Speaking of Refresh rates, when I posted my
WIP to youtube, I noticed it included 2 frames of my encoder logo, even though I used Trim(121, trimFrame) to skip the logo, yet it still showed up. I have a feeling this is due to the refresh rate or something, as Splatterhouse runs at about 60.606 FPS.