Though I know emulation isn't a very popular topic here, I thought about notifying of the news.
From GrooyMAME v0.205 the CPU % slider accessible from the sliders menu ingame now saves your settings in the game's dedicated .CFG file that's automatically created and updated when you play.
The difference it makes compared to before is that you no longer have to do the extremely slow slider underclocking every time you play.
Therefore it is now much, much easier for anyone who would take on the experiment to find out which tweaked values make the CV1000 games run closer to their expected behaviour (slowdowns)
Of course there's also the Blitter Delay slider, whether we're supposed to use both sliders in conjunction to try and find the right balance for each game is still entirely up to investigation and experimentation.
Hopefully with time people will report their findings and a database of settings will build up, making playing these games with emulation a more acceptable deal if not perfect, but at the very least better than before.
Anyway, interested or not, now you are aware.
NOTE: currrently HLSL is broken in Groovy, so some might prefer waiting for v0.206
