Can I make a feature request here? If not here, then how?
Please add joint MOBI file detection (e.g. files which contains both MOBI6 and MOBI8). Such files are problematic because calibre can't reliably change metadata. See
https://bugs.launchpad.net/calibre/+bug/1532161 for details / example of such file. Kovid Goyal suggested this FR.
Thanks.