Yep, I thought this would be a longshot. I'm already doing what you suggest (in a slightly different way) and of course it's far from real-time.

But if there's any enterprising electrical/audio engineer out there that wants to make their first $10M, think about patenting and building this wink

One form factor that would work is a Stage Prompter


https://soundcloud.com/user-646279677
BiaB 2025 Windows
For me there’s no better place in the band than to have one leg in the harmony world and the other in the percussive. Thank you Paul Tutmarc and Leo Fender.