I'm 100% with you on this one. Not having a plasma heat exchanger was a huge miss.
This is on brand for Space Age, though, and it's the thing I hate most about the expansion. "No no no, you're supposed to make solid fuel with all the extra ammonia and burn that in the heating towers plastered all over your base. That's how we intended for this planet to be played."
So many cases of this, where there's a clearly "intended" way to do things, and as a result less freedom to be creative in solutions.
Sorry, off topic.