Thank you for adding support for custom fonts!
However, I found the lack of a progress bar (or explanatory message) very confusing. I had selected about 10 fonts to upload, all at the same time, and it took several minutes to happen. I had to check my network monitor to make sure the upload was working.
I appreciate the sync icon was also spinning, but that's hard to see from the font upload dialog. If you don't want to code a progress bar, at least display a message to say that the uploading is happening in the background. This should be added to the online help page too.
