Okay, i’ll try to make direct suggestions, keep in mind i am ignorant in java, so i might tell something unreasonable, i apologyze in advance
Rotarycraft aeroderivative
I would add a sort of “<insert material>,<insert manufacturing> rotor” item
Maybe with max two choices each
Say,
Materials: nickel superalloy/nickel superalloy + cooling (would represent TBC and cooling conduits)
Manufacturing: solidified/single crystal
I guess it might work like the CVT? You put the rotor item inside
At the end of the day you give me a reason not to just slap in a second turbine. (one could go a little “creative” with the gain in efficency) and maybe it feels more techy
Maybe a machine with weird recipes to produce those sofisticated blades?
But i almost have no idea of how they manufacture those, i’ve only ever seen a weird furnace with an helicoidal path at the bottom
Regarding the reactorcraft turbines: i think one could play a little bit with a “suff vs temperature”
Ideally
Cheap materials—-> need more water for the same heat absorbed to keep the temperature low——->bigger water supply infrastructure, more turbines
Also, peak temperature of the cycle is lower—-> less efficency
Action vs reaction stage:
reaction stage is more efficient but power output is lower( and also pressure/temperature drop) so again
Steel/nickel ,action/reaction stage and play a bit on whether you want more efficient, more expensive turbine or not
To be honest i like the aeroderivative suggestion the most