Let's assume that
AP1 is on channel 40 width 80mhz, AP2 is on channel 48 width 80mhz, It overlaps.
As far as i understand 802.11ac has a functionality which detects width utilization per-frame and falls back to a much lower channel width. If AP1 detects AP2 and vice-versa they can go back to their main 20mhz and they might not overlap if they stay like that.
I never found a standard name for this functionality, there is 'Clear Channel Assessment', aruba calls it 'dynamic per packet negotiation of channel width', there is a lot more.
What i do not understand is how this could not cause issues like interference, for example, if they try to communicate at the same time at 80mhz
