That's a very good question.
There are two types of lamppost chargers where I live.
The majority are simply next to a parking bay, meaning that the usual parking restrictions apply (Resident Parking Permit holders, or Pay-and-Display). There's a polite notice on the lamppost asking motorists to be considerate and leave these bays to EVs if other bays are available.
The other type are lampposts where the parking bay next to them has been designated as 'Electric Vehicles Only'. On these bays, you must have a Resident Parking Permit to charge there, the EV can only be parked while connected to the charger, and the maximum stay is 12 hours. There's at least one such dedicated parking bay on each stretch of road.
I have to say that at current no one seems to take notice of the polite notice on the lampposts that are not dedicated to EVs, and people simply park their ICE cars wherever they want. Obviously, the rules for the dedicated charging bays are adhered to, presumably for fear of getting a PCN.
This has not been an issue so far though, because as I pointed-out previously at any given point in time the majority of chargers are not being used, and I've yet to run into an issue finding a free charger and bay in the vicinity of my house.
My expectation is that as more and more people get EVs, the Council will probably convert more generic parking bays to EV-only bays.
It would however be foolish to do this too soon, because it will 'rob' ICE cars of parking bays for no obvious reason.
On the same note, my car was down to 50% this morning and so I decided to top it up to 80%. The lamppost with the generic bay in front of my house was taken by a car that wasn't charging. The dedicated EV bay to the right was free but the charger was faulty. The dedicated EV bay on the other side of the road was free and operational so I am currently charging over there. It's right outside my front window , on the other side of the road. Because it's a dedicated EV charging bay, I'll need to move the car within 12 hours of parking it there. I'll probably move it as soon as my app tells me that charging has been completed.