Hey all, back from Ottawa. It was wonderful, thank you to our friends up north for being great hosts.
Still chasing the 1A5EA bug, seems like it could have something to do with sounds based on the disassembly and trace logs in that area of the ROM. Maybe an overflow of memory or something, I dunno. I've had difficulty recreating it in the Gens emulators with tracer tools, so it's hard to figure out exactly what's going on.
For now, I have managed to avoid crashes by disabling this setting under Emulation Hacks on RetroArch. It hasn't caused any issues in anything else for me, but has saved some time on not needing to restart my ROM once in a blue moon.
Still exploring more permanent solutions, and I will keep you updated