Good afternoon,
Speaking from my own experiences with the EE Smart Hub i feel the best option is to go down the 3rd party route if that's an option for you. Yes it means more cash out of your own pocket but the EE Smart Hub isn't fit for large households with a busy family in my opinion.
I have a modest modern new build house and upstairs in my furthest away bedroom i would suffer from drop outs and a weak signal. With 3 kids and a host of smart devices i felt the only option was to invest in a fit for purpose mesh system and since then i have had no issues what so ever with signal or drop outs.
I would imagine an extender of some sorts would work with the smart hub but it would all depend on the signal the extender can receive in your low/no signal part of the house.
