"Suppose an item was squawked then MELed, example an ELT, and the MEL said this item "may be inop for maintenance" , fairly vague isn't it.
How would y'all interpret this... ok for regular flights, or MX flights only?"
Perfectly legal. The far's allow for the elt to be removed for maintenance, I think it's limited to 90 day's.
If the mel is for a 135 operation, then it's been ok'd by the companies POI also so there's no conflict there.