im not sure if its a glitch or if it has something to do with the buffing mechanics, but when a broken engine is buffed and remaines broken some of its functionality seems to return.
for example my squid had all of its engines broken, and the engi buffed them all instead of repairing them, and i was abel to turn and move forwards / backwards slightly
so does the buff hammer give a 25% boost to the current output of the engine, or 25% of its maximum output?