I just bought 2x hAP Lite Classic for home. This is the idea:
1. One of the MT's will be the "main" home router. It connects to the ISP on eth1 and with a Set Top Box and a PS4 on eth2 and eth3.
2. The other one is in the next room, and has another Set Top Box connected to it. This MT should be connected to the first one via WiFi in order to connect to the ISP.
3. The second MT should also act as a WiFi repeater, rebroadcasting the same SSID and everything in order to widen the WiFi range.
So far, I have connected the first MT to the ISP, so the WiFi from it, the WAN connectivity and the first Set Top Box is fine. What is left is to connect the second MT.
Please advise. My WiFi knowledge is on an end-user level, so I don't know how should I accomplish this. I read in Internet for days, but every post and website suggests a different approach.
I will attach an awkward Paint-made topology as well.