I'm familiar with min RSSI from Unifi and Cambium, and do understand what your trying to say. But the thing is, I can't find any option for min RSSI in OpenWrt without using FT or others. All I wanted to know if there's an option for setting minimum RSSI. Every other thread is referring to a script, patch, hack, mesh, FT...
Ah... ok. Actually, I don't know. I just looked in the wifi parameters wiki, and I'm not seeing anything that applies. That may be why people have resorted to scripts and hacks.