I attached an Improved Trap Extractor, and got a help message in the log saying:
"The Imp. Trap Extractor is "overloadable", activating it again increases its output for additional resource cost, and may damage the unit.".
It's clearly not what it's supposed to say. It was the first overloadable part I've attached, but it's not the same kind of mechanic as with other overloadable parts...