There are some hooptech hoops labeled for shoes, but they are machine specific. Not worth the effort in my experience, but mileage may vary. I never really went after that market in the first place.
i would be interested to see how you embroider on shoes AFTER they're assembled. never heard of it.
It's not really any different compared to hats. Some spots it's best to embroider
before everything is assembled, some spots can be done
after (although it would still be best for those spots to be done on the flat versus on a curve, but I digress).