Not entirely sure if it's what was intended with "Mod request" in mind (I suck at reading intention, sorry!) but would it be possible to use some sort of frame-blending/motion blur shader to replicate the persistence of vision and (Possibly) interlaced (Blended) signal the original game expected?
For example, take how when use an "All" type of magic, you get a pointer finger rapidly flicking between all valid targets. I imagine on a CRT (I've only got a tube telly, no monitor, and unfortunately the game won't run on my Xbox's ps1 emulator to verify this) that it would blend nicely into a transparent icon, which I assume was the intention, is that right? As well, wouldn't it smooth out those jittery 60fps battles? (The whole point of motion blur being to create the sense of motion when there's not enough drawn frames to portray movement.)