Unfortunately, I only use Linux and can’t repeat the test. But the borg backup configuration directory copied to the UDF-formatted USB flash drive looks like this:
# ls -lhR /media/usb0
/media/usb0:
total 0
drwxr-xr-x 2 root root 268 Jan 23 15:20 backups
/media/usb0/backups:
total 12K
-rw-r–r-- 1 root root 130 Jul 10 2019 40-backup.rules
-rw-r–r-- 1 root root 74 Jul 25 2019 backup.disks
-rw-r–r-- 1 root root 58 Jul 21 2019 backup.sources
-rwxr-xr-x 1 root root 12K Jan 23 15:20 borg_autobkp_all_repos.sh