I've been using Shmupmame to run tgmj and tgm2p. tgm2p seems slightly more responsive in regards to inputs, but I just figured this was due to it being a later release. Recently, I read here (https://tetris.wiki/Modded_MAME) in the notes that "It maked [sic] tgmj less playable due to the introduced processing overhead, but tgm2 and tgm2p are fine". Is there something more optimal to run tgmj on, besides an authentic board? My apologies if this question has been answered before and is redundant, I couldn't find anything about this.
o/ tetriscrab i'd suggest trying a separate version of mame for tgmj then https://www.mamedev.org/release.html not sure if this is optimal.
Both tgmj and tgm2p benefit from the changes in mametgm, namely the diagonal input filtering and increased poll rate. Tgm2p sees the greater improvement though because of the removal of a frame of lag inherent to the Psikyo architecture that the game runs on, which does not affect tgmj.