Lord help us
If a washing machine's only USP is its ability to email/sms when it is done.
Frankly some of that list have to be marked as either
The totally useless
The totally obvious
Where are the developments in WiFi that stop channel collisions? Why aren't they doing frequency hopping? etc etc.
When every home in a 300m radius has their own WiFi setup and most of them on the same channel using it at peak times is a like going back to 28.8kbaud modem days.
Getting that sorted rather then messing around with range which will only make things worse would be a far better USP that that load of tosh.