It hasn't ever really occurred to me that getting something for people getting married that isn't on the list is bad, as long as I'm confident they'll like it. Though I mostly make a piece of stained glass as a present as it feels more personal.

I think the point of the list is so they don't get inundated with random stuff they can't use, and to help people with buying gifts, rather than being really strict and forbidding getting them anything else. If you're that close then the more personal option is definitely what I'd go for - it might even be a bit odd if you're that close to only get something from the list (mm helpful overthinking)