I think it would be a nice idea if you can direct the focus to the right tab from the program. Add a Virtual port to the tab widget and then with the same functionality as with menu
So if you want the focus on the first tab and the tab would have port V20, you would write in the program : Blynk.virtualWrite(V20,1);
This way it is a lot more flexible in ones interface design.
It would be cool to know the current active tab, mostly I need only to see/get data for the tab I am looking at. This would reduce also the size of sent data from hardware to server.