Comment # 26 on bug 1165780 from Karl Mistelberger

With a fresh install of Tumbleweed 20200416 the problem no longer persists.
Units
btrfsmaintenance-refresh.path and btrfsmaintenance-refresh.service indeed wait
until local-fs.target is reached.

However due to btrfsmaintenance-refresh.service being enabled the unit runs
during boot without /etc/sysconfig/btrfsmaintenance being changed:

Apr 20 12:59:51 systemd[1]: Started Watch /etc/sysconfig/btrfsmaintenance.
Apr 20 12:59:51 systemd[1]: Starting Update cron periods from
/etc/sysconfig/btrfsmaintenance...
Apr 20 12:59:51 btrfsmaintenance-refresh-cron.sh[1089]: Refresh script
btrfs-scrub.sh for uninstall
Apr 20 12:59:51 btrfsmaintenance-refresh-cron.sh[1089]: Refresh script
btrfs-defrag.sh for uninstall
Apr 20 12:59:51 btrfsmaintenance-refresh-cron.sh[1089]: Refresh script
btrfs-balance.sh for uninstall
Apr 20 12:59:51 btrfsmaintenance-refresh-cron.sh[1089]: Refresh script
btrfs-trim.sh for uninstall
Apr 20 12:59:51 btrfsmaintenance-refresh-cron.sh[1089]: Refresh timer
btrfs-scrub for monthly
Apr 20 12:59:52 systemd[1]: Started Balance block groups on a btrfs filesystem.
Apr 20 12:59:52 systemd[1]: Started Defragment file data and/or directory
metadata.
Apr 20 12:59:52 systemd[1]: Started Scrub btrfs filesystem, verify block
checksums.
Apr 20 12:59:52 systemd[1]: Started Discard unused blocks on a mounted
filesystem.
Apr 20 12:59:52 btrfsmaintenance-refresh-cron.sh[1089]: Refresh timer
btrfs-defrag for none
Apr 20 12:59:52 systemd[1]: btrfs-defrag.timer: Succeeded.
Apr 20 12:59:52 systemd[1]: Stopped Defragment file data and/or directory
metadata.
Apr 20 12:59:53 btrfsmaintenance-refresh-cron.sh[1089]: Refresh timer
btrfs-balance for weekly
Apr 20 12:59:53 btrfsmaintenance-refresh-cron.sh[1089]: Refresh timer
btrfs-trim for none
Apr 20 12:59:53 systemd[1]: btrfs-trim.timer: Succeeded.
Apr 20 12:59:53 systemd[1]: Stopped Discard unused blocks on a mounted
filesystem.
Apr 20 12:59:53 systemd[1]: btrfsmaintenance-refresh.service: Succeeded.
Apr 20 12:59:53 systemd[1]: Started Update cron periods from
/etc/sysconfig/btrfsmaintenance.

Disabling btrfsmaintenance-refresh.service and enabling
btrfsmaintenance-refresh.path fixes this:

Apr 20 13:08:44 systemd[1]: Started Watch /etc/sysconfig/btrfsmaintenance.
Apr 20 13:08:45 systemd[1]: Started Balance block groups on a btrfs filesystem.
Apr 20 13:08:45 systemd[1]: Started Scrub btrfs filesystem, verify block
checksums.
Apr 20 13:09:35 systemd[1]: Starting Update cron periods from
/etc/sysconfig/btrfsmaintenance...