Libraries should be able to write off fines accrued between a range of dates in bulk.
It looks like we have a script able to do this now: https://git.koha-community.org/Koha-community/Koha/src/branch/master/misc/cronjobs/writeoff_debts.pl 'ab|added_before|added-before:s' => \$before, 'aa|added_after|added-after:s' => \$after,