I got very distracted yesterday (and the day before? time is a blur) on things that didn't pan out. Today, I did manage to work on Edit Profile though!
First, I discovered that the API was working completely fine... I just had the "Request" tab of RapidAPI selected so I was seeing the multipart form data instead of the response. I'm a dummy!
This meant that uploading was working just fine, so I wired up the endpoint for updating display name and bio and we were good to go.
There's a nice transition and spinner when the image is uploading, and an alert when the profile update is successful. I also implemented sharing your profile's URL from the new Account view as well.
All of this and a little more are on the way in the next build.