Mesh/Extending options with RAXE500

I have a RAXE500 router as my main router and am trying to setup an access point/mesh/extender for my upstairs.  The location is far enough from the main that Wi-Fi signals are very weak and I have several IOT devices that cannot connect so far away.  

I've tried the Mesh extender (AC3000 Wi-Fi Mesh Extender (EX8000)) but it's not a viable options since I need to have MAC access control on and the extender modifies the MAC.

My current solution is a R89000 with dd-wrt software but it was damaged in a lightning strike several months ago so it's down to two ports.  It works great but would like to remove it in favor of a multi-gig switch and some sort of access point that will tie to the RAXE500 seamlessly.  I haven't been able to find anything compatible so far.  

Suggestions?