Currently, if you run multiple instances on a server, you can not easily configure for some, but not others, that holds not picked up will automatically cancelled. The cronjob used is: misc/cronjobs/holds/cancel_expired_holds.pl If it's scheduled, the feature is active for all instances - or you'd have to maintain a list, change the default cron files etc. It would be nice if this feature was tied to a new system preference, so that you can easily activate/deactivate it from within Koha and without accessing the server. This might also be useful for libraries that want to wait a little longer with cancelling in some cases, for example after a holiday period or when the library has been closed for a while.
This would still be nice to have :)