Finally put some time in on this.
Thanks for confirming what I suspected.
Infinitely. I've even looped it 2x a few times and 3x once.
AFAICT, there's only a few modes where changes are significant, and most of the time the modes are EASIER.
For WTW and LC, the game just takes away the orbits/ramps, but you can only make those complementary shots once anyway, so if you've made them both, there's no change to shots lit. DLLAL adds the inlanes to shots available, so that mode becomes way easier. BITS adds the Aerosmith targets which changes the mode from pretty much impossible to very doable. Sweet Emotion gets absolutely no change in shots at all (this seems to be a +30 seconds, however, as opposed to most other modes +20s). Obviously N/A to Klingon and Megatron, and not totally sure on the others yet. I know Rats adds the spinner somehow, but don't get how it counts unless it just adds points.
I retract this because now having played it it doesn't seem to be accurate. All I know is I was getting around 17/34M/shot.
And now for some tidbits that don't seem to have been mentioned before.
I lit medley for the first time tonight, and drained before collecting. Cue glass smashing.
Second time I had it ready to go, I was in the middle of elevator. After I trapped up, I realized elevator was the last mode I had to win. Oh shit. Make a couple more megatron shots, drain. Catch ball on right, compose myself, shoot scoop.
Mystery award: add-a-ball. Oh, shit. OK, guess I have a shot at finishing.
Then Medley ALSO starts. Sweet.
I ignore Medley to finish elevator, which I do. Then proceed to drain out of Medley with 1 target left on first song.
But then I nail the scoop on one shot to start Final Tour
Didn't finish Final Tour, wound up with 743M.
Don't know if Medley would normally resurrect Elevator or if I just got extraordinarily lucky with the add-a-ball and Medley start, though. Guessing the latter, tbh.