As of the 3.7.6 World SDK release, we now have separate build & test vs build & reload actions. The problem is in "Build & Reload", the clients value is still selectable and editable with no visual change, even though it doesn't actually launch a client.
This behaviour is unintuitive - the clients should probably be greyed out or hidden under "Build & Reload". This should also apply to all other UI elements in that area aside from "Platform(s)", as none are relevant when you are only doing build & reload.
I vote for greying them out personally, but hiding might make more sense.