The entire "X level against temperature attacks", it's more like resistance to temperature attacks more than specific AP attacks. Though I understand that this could also mean "Fire attack that has X tons of force won't damage them much" though that can be complicated as well.
Level against temperature attacks is really stupid and I've repeated this many times. That has nothing to do with force, it actually makes zero sense and has no reason to exist. Yet no one cares to actually do anything about it and just ignore people if they try to bring it up.
It is meant to be resistance to temperature, but that logic fails horribly. Since temperature resistance is about... well temperature. Saying someone has 7-C resistance to heat/cold makes no damn sense. Since a 500 degree fire that covers a large area can be 7-C, but a 2000 degree fire that covers a smaller area is only 9-A.
The "AP value" we have is nothing more than the energy it would take for an area/object of whatever size to reach that temperature. So just because you resist a fire that is 7-C, doesn't mean you can resist a fire that is 9-A. Due to the fact that flame is many times hotter than what he can resist.
Basically saying X value against fire/ice attacks is worthless as it doesn't meaning anything. In order to have worth you need a universal/shared energy system. Where you can use that same energy for something other than temperature feats, like enhancing your physical strikes or a big explosion.
Sorry, that's just a personal rant I've had for awhile. I really dislike these kind of "ratings".
Shoto defeating a weakened Shiggy is pointless. Jet Kindling is the same as Jet Burn, so no duh they both carry force. Instead that is a feat for the weakened Shigaraki, not the other way around. His Flashfire Fist is already on par with Endeavor, there is really no reason to mention it other than the fact it sounds cool to have.