This happened a while ago (but within last 2 years). I'm posting it now, because I wanted to be sure it was not associated with my most recent study section.
The proposal was from an experienced PI. I don't remember, but it could have been 2nd R01 or at least a post K22/23 level person. The person was not just content with shaving the margins down to the minimum, using the smallest permissible font, and making captions on the figures
As I have often said, there is lots of argument about how your proposal should work. (see here and here and here, but remember rules have changed since some of these things were written). Certainly, do not push the legal limits. But I always feel that big enormous communist-era blocks of text are depressing and dispiriting to a reviewer. If I turn the page and see solid top to bottom, left to right text, and my heart sinks. I am going to have to work very hard to be your advocate for a proposal like this.
This proposal tried something I've not seen before. They added footnotes. FOOTNOTES. Who the heck in science uses footnotes? The footnotes were also in a
font. I figured they got another 1/2 page of text this way. The footnotes were "definitions" of concepts. Like hopping. Or justifications. Like why we used bunnies. There was a debate (oye, are there debates), as to whether we could dock the score for such a blatant disregard of format rules. The answer from the SRO, was no, we can't. But I know that no one wanted to be the advocate for this proposal.
I have always thought that page limits/word limits are your friend. They tell you how much information the reader is expecting. How much you should include. If it is not enough room to say what you think you need to say, you are trying to say too much.
Protip: don't do this. The study section was irritated, and, I believe (although was not explicitly informed) that the proposal got pulled.