Came across this post looking for a solution for a very similar use case - thanks for all the great info guys!
Basically I'm trying to have a set up whereby I have a 802.11ac router with its own SSID and OpenVPN config all ready to go, and simply need to repeat a WiFi signal when I'm visiting clients. Weight is not really an issue for me as I often spend a couple of weeks at on a client premises but I want to be able to "config and forget" my router for about 5 devices. So all I have to do each time is simply to get the router to repeat the signal of the client's WiFi.
Just to confirm my understanding - the GL-AR750 would be able to do that, wouldn't it?