Keep SmartConnect
disabled for best performance results and better clients management,
@wmmallette47- it's disabled by default in Asuswrt. Connect slow 2.4GHz devices to 2.4GHz SSID, faster 5GHz devices to 5GHz SSID. Use
any 2.4GHz channel with higher bandwidth available - no one around you follows 1-6-11 rule. It's valid only when you control all the APs around, in conference halls, warehouses, etc. Your router can deal with interference well and will push higher throughput on "non-standard" channels.
Avoid DFS channels for more stable Wi-Fi.
Avoid 160MHz wide 5GHz channels, they require DFS use. Test lower 5GHz channels first - 36-40-44-48. Most ISP equipment prefers or comes locked to channel 36, try 40-44 and you may get better throughput, depending on your Wi-Fi environment. Best channels in my area are 4 @20MHz and 40 @80MHz, for example. Don't follow blindly other people recommendations, do your own research, experiment. Once you find your best channels,
don't change them often. Hold your ground and neighbors' equipment on Auto will move away. Most equipment around you is perhaps on Auto. Most Internet users don't know what Wi-Fi channel is.