Problem was: the change was explained in terms of user persona and their workflows, but there was no mention of user tests...
The number of times I've wanted to save in their native XCF file format is... zero. But I always want to save in a standard image format, and I don't really consider that to be exporting, just saving.
I understand why they wanted this, but I don't think many of their actual users did.
Users would be seriously upset if they made JPEG the default and the native format a buried option. People would be losing data left and right.
Saving in the internal format is probably rare if you’re just a user, but if this is a 40 hour a week job, then the compute time savings and potential disk space saving from doing that might be worth it.
Having to cancel out of File/Save and go back to the File menu and choose File/Export, over and over and over in software that defies this convention, is incredibly irritating.
The obnoxious thing is separating "save" and "export" into different menu items. Much (most?) software lets you choose "save as" (including saving as a different format) from the regular File/Save dialog. But Affinity Photo (and apparently GIMP) forces you to cancel out of the Save dialog for the millionth time and go back to the File menu and choose "Export." It's annoying and unnecessary.