if you can implement it it could be nice to have quality augment the maximum temperature of reactors and heat pipe. because when you have a better quality reactor and you're not using the entire fuel it reach 1000 too fast and the fuel is wasted.

That's an interesting idea.

I could alternatively just scale heat capacity and transfer rate, which would solve the fuel waste issue without complicating circuit logic - that might also help with "negative quality" mods, where otherwise sufficiently bad qualities might not reach the necessary temperature for heat exchangers to activate.
It would also make it easier to mix components of different temperatures - though it might also be interesting to use lower quality heat pipes to restrict the heat flow in certain directions, but that would be possible in either case I guess.

I could probably also add an option to make quality heat pipes increase their ambient heating range (for Aquilo etc) - there is another mod that does this already, but I'm trying to unify all these quality scaling extensions in a single, highly configurable package.

(Though I should add that a single fuel always produces the same amount of heat, no matter what quality of reactor you are using. Higher quality reactors just do all of that faster. But the higher capacity/temperature would still be useful for setups with high adjacency bonuses or modded larger fuel items)

Implemented in 1.3.0.

Failed to load mods: more-quality-scaling/data-final-fixes.lua:397: attempt to perform arithmetic on field 'heating_radius' (a nil value)
stack traceback:
more-quality-scaling/data-final-fixes.lua:397: in main chunk
when I activate heat settings

Fixed in 1.3.1.