Public Base URL for a 3scale-managed gateway allows localhost domain

Current behaviour

I can configure the Public Base URL for my 3scale-managed gateway to be a localhost domain. This causes zync to delete routes.

Expected behaviour

I can only configure the Public Base URL of my 3scale-managed gateway with public domains so that zync can correctly manage those routes.

I don't see any benefit to allow localhost domain for the 3scale-managed gateway, it only makes sense to allow this for a self-managed gateway. If testing of a 3scale-managed gateway should be done from inside the container then the public hostname should be passed via the Host header anyway. Should there be some validation on the system side to not allow this via UI nor API? Especially for 3scale-managed gateway.