I have Tado TRVs on my rads. I like the system overall. Batteries last a long time. App is good and has plenty of useful features. You do need to pay 2 quid a month or something to enable things like automatically turning your heating on/off when you are out of the house or on the way home.
I...
Any future work to the wall would require a new party wall agreement anyway. Unless you want the wall torn down for being over the property line whether or not there is a compliant notice in the past is irrelevant if there was no damage to the rest of the property.
If you're keen on extending...
I am (trying to anyway) building a loft conversion. This is a (not very upmarket) terrace in London so with a freeholder on one side and a house split into 2 flats on the other.
I have signed agreements with 2 of these and have a PWA on the way with the 3rd and they all seem on good terms...