Tried both, went nowhere.
@kepstin’s magicisrc seems to be outdated: Looping authorization, ISRC:s that will not be submitted nor deleted from edit view, and are remembered thus stuck; and recordings have the expected titles but wrong MBID:s. All I got was this blank-named octet-stream to save/open which I cannot.
@JonnyJD’s isrcsubmit.py is a zip (Win) done and dandy, but the README.txt tells me to stop reading, and its only .exe just flickers black and that is it. Maybe because it is 32-bit and no 64 available? isrcsubmit-2.0.1.tar.gz is another one, too other for Win7 and 7-Zip to handle, and latest action at https://github.com/JonnyJD/musicbrainz-isrcsubmit “4 years ago”.
Every now and then EAC picks up ISRC:s at rip, and it would be nice to batch-add these.