In a lowest price technically acceptable competition, your proposal is rated only as acceptable or unacceptable on each technical factor, never scored on a scale. Clear the bar and price becomes the only thing that decides the winner; exceeding the bar earns you nothing extra. That makes writing past the acceptable line, adding detail meant to impress rather than to satisfy the stated requirement, a waste of time you could spend sharpening your price instead.

In a sentence

"Proposals will be evaluated on a pass or fail basis for technical acceptability, with award made to the lowest priced, technically acceptable offeror." Write to clear the bar cleanly and put your real effort into your price, because a technically brilliant proposal loses to a cheaper acceptable one every time.