Hey. Thanks for the report. I can confirm that Rubia by default does NOT block train stops, chain signals, nor Transatlantic Metallocoasyphyxiation. Space Age does not normally have a temperature surface property, so it seems that some other mod is defining it, and giving Rubia a default value that is unreasonably cold.
I'm going to try some things, but this will 100% come down to some other mod coming in and messing with Rubia.
From my short testing, Freezer-Forked is responsible for making my surface temperature 18 K >:(
Cerys is for some reason messing with that recipe's temperature restriction.
I can probably tackle the 18K issue, but I would need more help from you to figure out: what mod that you have is messing with the train stops and rail stops?