Replay ID 3183004
21:30 into the game, I (dark blue) order all my T1 engies to assist the (still unfinished) smd building. They do that at a cost of 6.4 mass/s each. Then the building finishes and they go on to assist loading it, for a few seconds at normal cost of 0.1 mass / s per engi, but shortly after at 6.4 mass /s per engi.
In my eyes definitely a bug.
Replay also ends at 35 minutes, while game actually went on for a total of ~80 minutes.