It would be nice to be able to query how many libraries use a combination of different sysprefs like "AllowItemsOnHoldCheckout = 1 AND AllowItemsOnHoldCheckoutSCO = 1". This could be available either through an API or the UI.
One actual use case I have in mind for this is to do a sanity check when we are deprecating or merging some sysprefs in Koha so that they are not used in an unexpected way.
I can do it for you (direct access to the DB) if you provide me the sysprefs you want to check.