I find it very reasonable for guests to be able to do /join. The issue with them not being able to use it is when there is only a trusted ranked person online and if the guest/crafter (myself) would be griefed, it is almost impossible to get a trusted over because of the lack of /join (especially in a flooded map already).
Not including their resource of being with a builder+ in their facility.
Not including their resource of being with a builder+ in their facility.