Solo looks are good but getting the right fit can take several tries, so I’d go into an apple store to try them all first. They are change size (not really) between a regular AW and the AWU as the AWU is wider, so the loops seems to get longer and thus loser so they aren’t totally interchangeable between watch form factors. Probably not an issue.

Some did make a small dime sized rubber loop that goes over the other side of the sports bands, up the length and allows for putting extra material into it. Essentally a watch band loop. Amazon may have them or alibaba for sure.