That idea is perfect for backloading.
DCX
Yeah, I'd have no problems doing that, especially if someone was just trying to free up a year.
I also think there'd be some percentage of salary per year that you could backload (and guarantee). Maybe you could backload 60% of current year, 50% of year 2 back to year 3/4/5 or whatever, but all of the money has to be guaranteed or something.
My main point is, there are enough "cap" admins, that we could certainly make things more interesting.
If someone wanted to do the diligence (I can't right now, on a brutal schedule at work) they could crawl the top 5 salaries per position in the league and derive the Franchise Tag value.