I managed to get a bit more length when I need it by doing this to my wrapper:
Custom Rod Builders Guild Custom Rod Builders Guild
Since I never wrap down at the chuck end, makes it a free 20" or so extension when I need it.
Could have doine something similar at eash section joint too. Haven't needed that extra length as yet. In those places I've use the thinner one-sided channel, and take a tad off the end of the supports for clearance perhaps.
I just never wanted to spend the $$$ on another piece of channel when all I needed at the time was an extra 6" or so in length