@superfromnd I got the game pre-patched initially, so a few minutes ago I decided to patch the original JP files using the tutorial from that website you linked. Each of the different checksums for the ISOs were the ones indicated and they patched with xDelta3 successfully. Loaded up the game and I still get crashes.
So I started thinking maybe the issue was to do with the files being split as .iso/.wav/.cue instead of a .CHD file or a .cue/.bin. I tried using Isobuster to convert it back to a bin/cue format and was able to launch the game but still got the same crash. I thought maybe I had done the process incorrectly so I found someone else's conversion to a .bin/.cue format and the game will still crash at the same point. I also found another person's version of the game in .CHD and yep, same crash.
the crash specifically happens at this point in the longplay above, where you examine the gun in this opening office segment. You can examine other bits like the cigarettes and the machine on the right, but clicking either the gun or the picture frame crashes it. I dunno what's going on with the saturn hardware wise, but it transitions into a still zoomed in image separate from the rest of the environment, and that's where the crash seems to trigger.
It's so frustrating that I can't really get any more information from yabasanshiro (I also don't seem to be able to get much from lr-yabause because it just hangs at the section as opposed to crashing outright).