When using multiple filters, blacklists seem to be ignored.

Current behavior:

Filter A is setup to allow the tag c:food.
Filter B is setup to deny Apples.
All food including apples are able to be inserted into the barrel.

Expected behavior:

Filter A is setup to allow the tag c:food.
Filter B is setup to deny Apples.
All food but apples should be able to be inserted into the barrel.

This is because at the moment all filter upgrades are considered separately and thus work in a kind of "OR" relationship so in your case it basically says it's either food or it's not apple which in the end means all items are valid because they are either food or not apple. I have a note on possibly doing AND relationship between allow list filters, will have to think about the combination of allow / deny list and whether AND will work there in general if so I will make it OR between deny filters and AND if there's a combination of allow/deny filters.

Maybe a tier three filter upgrade that only allows for filters to be inserted into it, which then functions as an And filter of all the lower tier filters inside it.

this was added now - any time a filter is set to block it will require item to match all the filters, the only time it's alright for item to match only one filter is when all the filters are set to allow