Industrial Clean-up

You certainly can do unstable steam reactor designs, you just have to pulse it more carefully to avoid over saturating the coolant. Especially with MOX where the heat can easily run out of control above 50%. To provide coolant is to only provide uranium to normal reactors after all, there is more in it than that.

To say not much more was added beyond the reactor itself is both naive and wrong. The outside stuff is very much part of the whole design too, IC2 has always lent itself towards bigger factory setups rather than compact single blocks, hence you have everything that needs to be outside the reactor to gain power from it. Kinetic and Heat both remain juniors to EU as it stands yet they provide future alternatives which EU alone struggles beyond bigger numbers. There is a certain amount of optional planning to do with designs as well to best maximise heat production for superheated steam => maximum efficiency rather than the much less efficient stirling generators.

Reactor components have always had a limiting factor of how interesting they can be alone when people will copy the most effective/common designs anyway. If there is more to the reactor than what is inside it, automation or not, blind copying is at least a little harder and so people might think about what works out best for how their base is laid out too rather than merely what the guide they're following did. In theory at least, people can still cut corners if they want.