An important thing to understand first about the AP adjacencies on that page are that these are RF related only and do not necessarily factor into needs for the key caching or other operations involved in roaming. The APs, if operating in AP mode, will be servicing clients and operating only on one channel. This means that the adjacencies you see will only be shown if both APs are on the same channel. This means, assuming you have a channel re-use plan in place, that you most likely will never see adjacencies on this page between two APs directly next to each other in your heat map.
The AP adjacencies page has two main benefits:
1. You can see if APs you have placed on the same channel are broadcasting at too high a power setting (meaning they will see eachother at greater that ~-60dBm).
2. You can view rogue APs and get a general area of where they are.
As for the setting you mentioned, if you wouldn't mind pointing out the specific one I would be happy to explain it in further detail.
I am marking this question as Assumed Answered. If you have anymore questions, please don't hesitate to respond to this thread.
ADTRAN Product Support Engineer