I'm not the world's biggest fan of the heat system overall, but I adapted as necessary. It's still entirely possible to misalign cooldowns or accidentally Overheat. I mean, you shouldn't, but raise your hand if you're not human and never make a mistake. And yes, some fights are quite irritating with interrupts, but it's your job to learn how to work best with it. When you know the encounter, you can time what you use and when much more effectively. That awkward break you mentioned used to happen a LOT more frequently, and not due to the encounter when heat was a +10, and things like Barrel Stabilizer had oddly long cooldowns.

I feel like a large reason MCH seems so inconsistent among the players is that the players are so inconsistent in what they want from it. Even SE noted that it was difficult to make changes based on feedback before 4.06 because the camp was so split. I honestly don't see how anyone at all has issues with the heat system as it currently works. ESPECIALLY when the old, common complaint about MCH was that it was "too complex". Maybe it's "too boring" or too simple now, but they took it from once again being misunderstood and excluded to being largely useful and favored for higher level content.