But wait a minute - shouldn't most of one's future-proofing be making sure you CAN easily alter a design later if need be (including better documentation), especially in the ways you can already see change coming?
Cleaning up existing code will make it easier to alter designs later and that's something you should continually be doing as you implement features and fix bugs, but that's not pre-emptive architecture.
As I say elsewhere here, I've killed projects assuming that. Pulling out bricks from the bottom and replacing them is sometimes so hard, you really have a dead project.
