--Question: anyone else been down this road? What did ya wind up
doing?

Depending on the project, I probably would have avoided the stops
altogether. Just set the fence for the first groove, rout all 6
pieces, and repeat for the rest of the grooves. There would probably
be situations where this wouldn't work, and it would be harder to go
back and do one more piece after you finished most of them. But it
seems like this mini-assembly line would be quicker and easier than
routing all the grooves in piece one, then the second piece, etc.
Regarding the parallel-moving fence, I agree with the previous poster
that your Woodcraft salesperson was misinformed - I know I've seen
fences that can be moved as you describe.
Good luck,
Andy