Currently I use a huawei 4g mifi on a boat. It has a WiFi extender option where the router will connect to the marinas WiFi if available and all my devices connected to my mifi device will have internet, if the boat is away from marina then they will still have Internet using the 4g connection to the mifi. The huawei doesn't support openvpn so that's why I'm looking at tp link options. Does the mr500 or 600 have the same feature?

Thanks in advance