Bah Humbug. It's not cheating. It's just being professional. If it was, mixing and mastering would be cheating. BIAB would be a crime etc etc etc.... Just my thoughts. The punters don't know or care. Most of them don't even know if you're singing in the right key

lol. If I could zap the guitar, I'd be tempted to use Karaoke files... Just do whatever makes you happy and gets you work.
I use BIAB live for streaming and my one man shows. I also play with other musicians just singing and playing guitar. I like the buzz of playing raw.