@galrob 

Hi, yes, and it would be great to link both of them directly to the main router since the network speed and stability would be much better, like:

RE505X#1----<Wi-Fi>--main router---<Wi-Fi>--RE505X#2

And have you ever thought of our Deco Whole Mesh system if you are going for multiple range extenders:

https://www.tp-link.com/us/whole-home-mesh/

Thank you very much.

Best regards.