My secret super power is making things short. It is enhanced by my second-in-line-power which is to write short in the first place. When I finished my thesis, it held the record for the shortest approved thesis in my department. It may still be, but I don't have lots of data to support that statement.
I have often said, here, in the tweets, to all my trainees till their eyes roll back in their heads and they fall out of their chairs in boredom:
Page limits are your friends. They tell how much the reviewer/grant-giver/journal/whatever wants to read. If you are having trouble "fitting it in", it is not the fault of the limits. You are saying too much. They don't want that much.
If you are a full page over, you don't need to go back and edit out single words. You need to go back and figure out which paragraphs can be reduced to a single sentence. If you are multiple pages too long, then you need to figure out what sections can be reduced to a single sentence, or even are totally necessary.
The ability to know what to put in a proposal, and not make type I errors (leaving out stuff that should be there) or type II errors (putting in stuff that isn't necessary), is a skill worth honing.