I'm not a programmer, or even a coder and really not even a scripter--I mean I can do stuff that works for me but I'd be embarrassed to show it here, for example, but...
A lot of times you can pick up things--I remember, though the memory is hazy, finding something (years ago, when we mostly used ports) something weird in the postfix Makefile that could be fixed, I don't remember what, but I was able to make a patch (which is fairly easy) and send it to the maintainer. As has been said, documentation--for example, I saw something missing in the dwl window manager man page, and was able to patch it, just by using the dwm man page (the two window managers are VERY similar), and the FreeBSD maintainer added it before the developer did.
Another example--I'm sorry to be so vague but this one was awhile ago too--dmenu (for dwm) had a problem. Doing a bit of web searching showed that the later version had fixed the problem. I sent a quick email to the maintainer mentioning this and they updated it that day or the next day.
The point being, that even not being a coder, you can find small errors, and, perhaps because FreeBSD is relatively small compared to Linux, you can let the port's maintainer know and they will often answer you, and utilize what you send. Also, as has been said, examples for the man pages might be useful. For example, say a man page is hard for you to understand, you do a bit of web searching and find a very clarifying example, send it to the maintainer. Often, if you open the man page in vi you'll be able to see the format and create a patch, even without a lot of knowledge.
I have a dated page, actually done by Josh Glover, and not even html, it's text, so you'd have to download it if you trust me,
https://www.scottro.net/qnd/qnd-diff-patch which covers how to create and appy a patch. It's not hard. You can try opening a manpage in vi and even play around with adding an example, then view your new page with man to see if it's done correctly.