Alright, am I imagining things or what? Either my feet are getting fatter (doesn't look like it, but then I never looked a whole lot at my feet) or my shoes are getting thinner, because shoes that fit fine before feel like they're not wide enough now. Fairly sure I'm too old for any bone growth.

Feet (and hands) can get meatier on T, which may be what's happening. Feet also get bigger as you get older -- they spread, or something. Mine are at least two shoe sizes bigger than they were when I was young.

When I was at my heaviest (well before I started HRT) my feet were a full size bigger than they are now, and I was nearly an inch taller. I don't think it was bone changes (or else I would imagine it would vary much more) but, perhaps connective tissue, muscle, etc. I measure myself alot and these were things I didn't expect, but as time goes on, I notice my feet don't continue to shrink so I am thinking it isn't all that variable.

don't know how old you are.  I grew a size from my early-mid 20s when I started up on T

This happened to me as well. My feet didn't get longer but they got wider.

So it's foot muscle. Didn't realize feet could develop much muscle. Thinking more on it, they used to look much bonier.
Thanks, everyone.

Dang, though, these shoes were expensive and I can't afford to replace 'em right now.

I am on the other journey.

All through my adult life I took size 10 shoes. After as little as 12 months they no longer fitted and my feet would just lift out of them when I walked. I now take size 8 and some size 7's if they are a wide fit.

If lacking T can make mine smaller, I could well believe that taking T would make yours bigger.

Enjoy