I once had a setup very much like that in DSL, and it worked well. This was at a time, though, when the number of loop devices was severely limited. After the number was increased beyond anything I'd use, I just started automatically mounting all the apps I might need for that day. The same seems to be true for tcz.
I could see this procedure being very useful for tce type extensions, since you don't want anything in RAM that you're not going to use.