It is likely that some additional advocacy, and possibly scaffolding, would be needed to support some of the gap-year options.
One of my siblings did a paid summer internship (so about 2 months) in a research group at a major STEM company at about that age, possible mainly because a member of the extended family worked there and was willing to 1) vouch for suitability, 2) act as host family, and 3) facilitate appropriate professional interactions. So that wasn't a full year, but might serve as proof of concept. String a few of these experiences together, and one could easily fill a year.
For myself, grade skips allowed time for multiple rounds of graduate school (all in different fields), plus a partial gap year at a more typical age.