That is so true, but it is the initial setup that we want that adjustability for. Different size books, displays , whatever. After that no one moves it.. agreed.
However, the only way I can think of to do
What I think I might do is take Swingman's idea, add 1/2 ply ... So take the existing 3/4 inch panels I have already cut, route part of the channel in the 3/4,
route the rest of the race in the 1/2 leaving about a 1/4" of thickness for the lip that hides the wire. Hopefully that would be enough thickness. I can glue the 3/4 and 1/2 together using either cauls or vacum bagging, but the vac bag might break the lip... there's a lot of force in vac bagging.