Due to the way reactors calculate their maximum heat level on-the-fly at every tick, heat exchangers that deal with the reactor's heat will work with incorrect( ? ) values.
Example:
Imagine a line of components: Reactor Heat Exchanger - 5 x Heat-Capacity Reactor Plating - Reactor Heat Exchanger
The 5 platings give the reactor a max temp of 20k.. lets say that the reactor's heat is at 15k:
The first exchanger is processed before all of the plates, it sees the reactor temp is 15k of 10k (150%) and tries to match that.. it melts.
The last exchanger is after all the plates, it sees the reactor temp is 15k of 20k (75%) and will try to aim for 75% too.
I'm unsure if it's intensional or not, so I thought I'd mention it here and not in public.