User blog comment:Willbachbakal/(Champion Rework) Rumble, the Mechanized Menace/@comment-25228021-20160909122125/@comment-1330314-20160910201145

I don't think making Rumble's heat decay change with stats would be the best idea, since that would risk seriously messing up his resource management. Again, his heat decay is mapped pretty much exactly on his abilities (his shield and its Heat cost both decay at the exact same time, for example, which is deliberate), and going even slightly one way or another would likely do him more harm than good.

As for Flamespitter, I originally debated whether or not it should be disabled while overheated, but I decided to keep it on, for two reasons: the first is that overheating would already put him at a big disadvantage, since he wouldn't have access to his CC, extra tankiness or mobility, the second is that Rumble already gets bonus damage on his basic attacks even on live, so he doesn't really lose access to damage while overheated (in fact, in some cases, he actually gets to deal more damage).