@manawyrm hm, after removing basically all calls to t6k11-related functions (and with build-fxg3a), it still failed
looks like it's caused by the audio thread using DMA channel 0 (channel 0 and 1 are reserved for gint tasks on the fx-CG50, 0 IIRC is for sending VRAM over and 1 is... something? I honestly forgot why it was used)
I think you'd also need to mess with the C0MID address used as it's hardcoded (I'd say my branch of gint defines fields for that, but the forge it's on is getting hammered by AI scrappers, sorry!)
Still doesn't seem to get past the introduction sequence, so I assume there's something wrong with the DMA code still...