It appears that custom tags that I've added via KubeJS:

  ServerEvents.tags("item", (event) => {
    event.add(`kubejs:ekof_processable_${rpm}`, itemName);
  });

Doesn't get recognized when referencing it inside of the Tag Export Bus:

Am open to contributing a fix if possible.

it won't work when hot reload tags, if you restart game it should work.
it has been fixed anyway