Next time I find myself with the right assortment of junk, it would be interesting to run a piece of optical fiber through UV glue inside an opaque enclosure and see if it helps the light get where it needs to go. There’s decorative stuff that glows from the sides with a visible light source so I’d expect it to do something worthwhile in that situation. Could be a waste of materials for almost every possible use but maybe it’ll solve a weird problem eventually.