There's ALSO an issue of where you draw the "toon force" line, just
look through this category. I feel like you'd have a pretty easy time arguing someone like Mario or Sonic are cartoony enough for the ability to apply to them, and at that point you'd just be able to immediately invalidate their current tiers by saying "oh they're only this strong like 1% of the time, here, add a 10-C end for the time they got hurt by something trivial, btw you literally cannot use them in vs matches anymore".
You can draw the line at "they need to be from an actual cartoon", but then you have a different issue of just randomly shutting out characters that clearly qualify as Toon Force havers, like
Peppino from Pizza Tower or Cuphead. Not only that, but it's not like all cartoons are the same. Bugs Bunny is way more inconsistent than Popeye, who is way wilder than Tom & Jerry, who are way more toon force-y than Ben 10. You can't draw a line, does anime count? It's just cartoons made in a specific part of the world. Do classic Disney movies count? How about Pixar ones? Does Spider-Verse count?
Back to the first paragraph, the "you literally cannot use them in vs matches anymore" bit wasn't hyperbole. There's no factor determining how a toon force character's power level behaves in any given circumstance, outside of the headcanon, vague ass "they're strong when it's funny for them to be that" idea, which is very subjective. Is it funny for Bugs Bunny to beat Darkseid in a fight? Maybe, but maybe I have a darker sense of humor and I think that Darkseid grabbing a beloved cartoon character and absolutely beating the shit out of him is hilarious. Maybe I don't think either situation would be any funny at all. You can't determine this sort of stuff, so characters who have toon-force based power variation would, by necessity, have to be thread-banned. You can't even lock them in any specific tier, because "
An exception would be if the restricted ability/technique has a separate tier from the main one, and is one the character can consciously restrict themselves from using. In this case, the match can be added." Toon force is basically always involuntary, so you can't lock it.
I should specify, when Toon Force is an actual, canon characteristic of a character, in something like Who Framed Roger Rabbit or
Slapstick, the Deadpool villain, then I do think that a "varies" tier can absolutely be discussed, this is just for when it's just something that characters abide by for comedy's sake rather than an actual canonical verse mechanic.