Yup, so much for theory (thanks nonetheless!). Only, if installing software on a device like a tablet, one doesn’t often check (or care) what folders it creates/uses.
In my case, I experimented with several dictionaries, KOReader, Librera, ColorDict and GoldenDict on my Android 4.4.4 Tolino Tab 8", to find which would work best with KOReader
and Librera.
So I still think some restriction to device folders scanned might be useful. Or, as I proposed in the bug report below, an initial selection by the user before the scan starts.
I feel that—for
inital scans—a restriction to the "list of folders on the device to which to send e-books" might be in order, to avoid scanning the whole device. After that, only scan what has been selected in "Change scanned folders" and
don’t auto-activate each new folder detected.
Thinking about it, that’s what I meant when saying "lock folders": Don’t auto-activate new ones. That should solve all these problems. For those who wish for "everything fully automated", maybe a setting like "Auto-activate new folders on device for scanning (Y/N)?"
Related:
https://bugs.launchpad.net/calibre/+bug/1943991 (Immense RAM usage due to scanning unneeded stuff; solved by manually editing
mtp_devices.json.)