Replacing a Range Extender

UPDATE: I HAVE SWITCHED FROM RELAYD TO WDS, AND NOW EVERYTHING IS WORKING AS EXPECTED

I currently have OpenWRT on my primary router with OpenVPN and Policy Based Routing to redirect a particular client (with a static IP address) through to my external OpenVPN server (different location). This is working successfully.

I also have a Netgear EX6110 WiFi Range Extender because the signal strength is weak in some places and running cables is not available. The aforementioned client, when connected to my router through this range extender, is also successfully "routed".

Because the signal strength/speed and reliability of this range extender is not as strong/fast or stable as I would prefer, I also have a secondary router running OpenWRT which I have setup as an additional range extender (paralleled, not seriesed, with the Netgear EX6110) configured with relayd. This router is successfully providing greater signal strength/speed and reliability, but the same aforementioned client is unsuccessfully being "routed" (using the same Policy Based Routing rule) to the OpenVPN server when connected to my primary router through this secondary relayd router.

From what I have read throughout this forum, it seems that relayd may be incompatible with this type of setup with Policy Based Routing. Is there an alternative to relayd that will allow this secondary router to function like the Netgear Wifi Range Extender and allow this aforementioned client to continue to be routed to my VPN by my primary router seamlessly?

Ex6110 is not among supported devices. Unikely any of wireless extension will interop with closed firmware.