I made a lot of PR for Chez Scheme (and indirectly Racket). For me it's easier to write the code, perhaps because I'm not an English native speaker, but my Spanish is bad too.

Most of my PR are like 30-50 LOC (including comments and tests), with a few very related features, and I have probably a 90-95% merge rate. Sometimes writing the explanation takes a long time. Many times while writing the code I get a lot of small surprises and unexpected corner cases. So most of the time a previous discussion would be too generic to be useful for me and inteligible for the maintainers.

Anyway, my idea is to take only a few hours (4?), perhaps distributed in a few slow days. So if it's not merged it's not a big deal, not hard feelings. Also a short feature is easier to review and modify if necessary.