The problem with restructuring a bunch of code to make adding a bunch of features much cleaner is that management wants some those features that I added after restructuring the code in an a branch that was made before the restructuring. And of course, the restructuring can't go into that branch.

That's what happened to me recently. Version 1.x had been branched off, and I did lots of restructuring of the main branch for version 2.0, as well as adding a bunch of features. Version 1.x.y was frozen except for critical bug fixes, but version 1.x.z given an extended schedule, and some features I put in 2.0 now need to be 1.x.z, and the implementations of most of those features depend in the restructuring to be done cleanly. I think I'll be hacking in throwaway implementations for a lot of them in 1.x.z.