Wait the Crystallization Crucible has a catastrophic Failure Mode? Its a heat powered Machine isn’t it? Those dont really explode unless you do dumb Stuff, at least the Basic Machines dont, Boilers and Crucibles do ofcourse.
And yeah, one reason the whole RU and HU Stuff is so complicated is to make using EU more attractive even if its less Efficient, while also giving a good way to make things more Power Efficient by NOT converting the Power.