I was trying to search on the Archives of Nethys for what happens to a character's clothing/gear when they use change shape . I couldn't find anything on the specific ability or even polymorph rules and transmutation rules in general, so I must be missing something!
The only other theory I could come up with is I'm not actually missing anything, there are no rules for your gear changing/merging/etc. so you have to strip before turning to a fox or back, and you better have adaptive clothing that fits both your tailed form and your not form if you have a tailless form...Of course, that would mean all of those battle polymorph spells would be a bit awkward to use, like dinosaur form would seem rather awkward to have to strip first!
In contrast, the enlarge spell actually does explicitly say what happens to your gear, which unfortunately lends credence to the "if it doesn't say, it doesn't do anything" interpretation, but that doesn't really seem like it would be RAI for combat polymorph abilities.
So...am I missing something, or is it really true that RAW most polymorph effects don't change what you are wearing with you? I am particularly interested in the Kitsune example, as I've been chatting with a friend who is playing one in a 2E game right now.