I've slept about this. If you have the time, you can take a shot at covering those -- if you're okay with doing potentially unneeded work.
Let's denote by "version A" the 0.7.9 physics plus (current branch phys) plus (current branch tumbler-rewrite).
With 0.9.7, all 113 levels are solvable, and in A, only 13 of the 113 break. It's likely, even though not guaranteed, that the final tumbler's sub-frame movement will be a mixture of the 0.9.7 movement and the A movement. Therefore, it's likely that either the old replay or your cover using A will solve it.
If you'd like to give it a go, and are okay with creating 13 replays that might not be useful later: I've rebased tumber-rewrite onto phys, you can thus build A from tumbler-rewrite.
-- Simon