@Quest7 

I assume each model and brand of router may be different in how and when it selects the channels in auto mode. Also your environment affects the channels used. It may select the best channel at the time and another router uses the same channel which was not very active at the time the router selected the channel. There are preferred channels that do not overlap and how much each router uses that to determine which channel may vary.  Does it use the DB level? Does it check all channels and in what order? Does it look for a specific set of conditions and if met use tht channel as searching channels takes time and resources? 

As far as when the channel changes, I do not know. I guess you could keep checking to see if it changes.

I would not use the Smart Connect feature of a router for several reasons:

• I prefer separate SSIDs so I can control which devices are on which network.
• There are several posts here where devices are placed on the less desirable network.
• Reports of issues when switching between networks
• Unable to control channels, band width, and other WIFI controls
• Smart Connect seems to be a poor man's Mesh system

If I wanted the features of Smart Connect, I would get a true Mesh system which is designed from the start to do it, not some add on.