My first game iteration plan includes quick-win options, as the quality of the first game is not supposed to be A1 but server as a learning exercise. I would imagine that the 2nd pass, or phase 2 would include using deltas and doing things correctly. Although I am under no specific deadline, I do want to draw Phase 1 to a close.
The next task after controlling game speed is to introduce sound, which I'm placing a higher priority on than a full rework to control game speed correctly. I guess it depends what's on your plan is for the implementation - and they are always pretty individual. I'd favour a patch-up for now. Just a preference though, and I'm sure others will disagree. If I can patch it up for minimal effort and it runs OK from the users point of view then that's fine for now.