Honestly this sounds pretty good to me. Unlikely to be accidentally triggered, easy to explain and run, lets you do it later rather than having to save things

Honestly this sounds pretty good to me. Unlikely to be accidentally triggered, easy to explain and run, lets you do it later rather than having to save things before continuing, and provides a few ways to preview the data before submitting (e.g. temporarily run a webserver to locally view and possibly clean up the report, which can easily include large files, and just click submit there to send it with CORS... or bundle it into a file that can be dropped somewhere if that doesn't actually work).