You know what I would love? It's probably too complicated and would slow down the site, but I know nothing about things like that, and maybe it wouldn't, so here goes. I would love another sort button on the author pages to sort one author's pages by CATEGORY. Clicking that button would result in the page shifting to a sort of mini "topics" page, with just that author's pages showing under each topic header.
As I said, NO idea if it is feasible, but if it is, and would not have undesirable consequences, that's something I'd love to see on the long-term tweaks list.