I had seen the plain old Kobo Utilities:
https://www.mobileread.com/forums/sh...d.php?t=215339
But hadn't seen the "Extended edition" you mentioned. Are you referring to Kobo Touch Extended?
https://www.mobileread.com/forums/sh...d.php?t=211135
Looks like that also suggests the two KePub Metadata Reader and Writer plugins. I'll have to read through those threads.
As to formats, the vast majority of my books are from Amazon (so, mostly AZW3 with a few MOBI). Is there an easy way to remove all my converted versions (currently all AZW3) and leave just the original files? Once the Formas get here, I won't need the converted Kindle formats any more and will just need files converted to EPUB.