Hello,
in the Android client the user can mass export blobs per category per user (sadly not all at once). The desktop client totally lacks that feature but really needs it desperately.
Greets!
Blobs of what? Mbox? You say “files”, so Maildir?
Maildir import and export is really useful. I support it.
I don’t know if it helps you, but on the desktop the blobbies seem to be already accessible without exports divided by account (and not by contact).
In linux: ~/.config/DeltaChat/accounts//dc.db-blobs
And now bunnybloobs fur u https://www.youtube.com/watch?v=TN75iUA0-Mw
DeltaTouch has a similar folder full of attached files. A long click on an attached image gets you a closeup with a download button. Swiping the file left and clicking the hamburger icon will also give you a save-file option.