Well when dealing with phone support they probably don't have access to bug reports or current and historical information. So on the cover, it's probably rosy to first level support. Reality for us says otherwise. They and anyone else can review this thread if they wish. The issue is being handled and hopefully will get fixed for everyone, globally with the 878. 
Yeah that makes sense.
By the way just to add, I tried enabling smart connect on 1.10 for a day. In the same room as the router devices would latch onto 5ghz but upon moving to an adjoining room they would continue to hold on to the now significantly weaker 5ghz signal instead of handing off to 2.4ghz.
Noticed huge drop in speeds in the adjoining room whilst on the weaker 5ghz signal so turned smart connect off and reverted to my earlier setup.
Same custom said for both bands. No customisation in the channel settings. Everything on default. Works much better that way. The devices choose the band depending on the signal strength.