Update: I'm now basically finished with my first playthrough, which I did on a real Saturn. First of all, it worked, so hooray! Second, I spent a lot of time doing script tweaking based on context that I was missing before, and that took care of a lot of important problems. Looking at some scenes again after this edit in particular, I'm feeling pretty good with the way this project is turning out.
Next is to wait for the hacking hurdles to be overcome. There are three big ones:
1. Settle on a print routine, possibly introducing a VWF.
2. Get the text that appears at the bottom of the screen to display properly. This window is used for both the item descriptions and the battle text. Right now, it's always empty.
3. Extract and edit graphical text. This includes the map, the room/path labels, and the thing at the load screen that says はじめから.
Once at least #1 is taken care of, and ideally #2 as well, I'll go in for a second and hopefully final playthrough using Yabause. There are roughly two dozen trouble spots in the game where we'll have to get savestates to solve the bugs behind them. I'll also do my final tweaking and take care of any issues with lines being too long to fit in text boxes, which could get tough but hopefully won't.
If anyone wants to lend a hand with the hacking, the door is still open.