Thanks for the reply!
There are some “band in box” type pedals that do stuff like that. Trio?
I was hoping EHX would make a pedal that simply generates a realistic bass sound that tracks the guitar input. I really like the other instrument pedals they have. Basically, the guitarist would have to play the bass line but get a bass and guitar doubling effect. I have tried octave down pedals, and they work, but the sound of the octave down is never quite like a real bass.