Conducting instrument approaches in uncontrolled airspace sounds dodgy to me. It sounds like an accident waiting to happen once sufficient traffic levels are met.
Lucky that Norwich has that little traffic they can have a BBC film crew in for the day fannying around with hot air ballons.
H'mm Airports round the UK with way more movements than Norwich but don't see the need for Controlled airspace, off the top of my head
Inverness
Blackpool
Humberside
Teeside
Cambridge
Wick proberly has more movements if you count all the helibuses transits.