WHEW! I'm worn out, but ... I THINK I finally figured it out.
I first encountered yet more hits & misses and inconsistencies and my CT-X700 was beating me like this and had me
But, after some more reading over and over, performing analysis and trial & error, I THINK it finally made sense.
I cleared out locations 172 through 176.
I then made it a point to keep every current song / medley always recorded at location 172 MltRec 1 ... and cleared it out before going to a new song / medley. And it WORKED!
I'll have to wait until tomorrow to try out the Settings Setup Savings in the Registration Bank bit.
Thanks for your help, Brad. I took the scenic route, but eventually, with your help I got with the program.