It'll take a while to re-unlock everything and get used to the normal control scheme, but in the meantime, I did run into one new issue:
In the Temple level, I had maxed Viscosity/Magnet, some amount of Compound Interest/Hot Start, Piercing 2, and Extra Ball 4 (so 5 total). Two seconds into the level, as all 5 balls simultaneously reached the top white part of the stage after cutting through the middle, the entire page and browser became unresponsive for around 5 minutes, until the page gave up with an "Error: 4" page.