I'm not sure my comments add a lot to whats been said already but I'll put them out there anyway
I've recently bought an eMoped (28mph, registration plate, helmet, insurance etc) as a replacement for my 170cc ICE scooter - and it leads to a certain style of riding due to its high centre of gravity and big wheels. I can't say I'm totally comfortable on it yet. The lack of 'audio feedback' from a motor is very disconcerting - the main/only noise is from the helmet visor. The biggest shock was the cost of the insurance which was no cheaper than the motorbike (about £140 for the year).
I really don't think that this type of machine is suitable for any significant deregulation away from its 'moped' classification based on my limited experience.
Equally Mrs M has bought a folding travel mobility scooter (Class 2) and, of course I've had a whizz around on it. There is no specific brake, stopping & slowing is purely based on the motor in the front wheel, and very effective. (The drive wheel looks remarkably like an e-scooter wheel). Being a 4mph pavement machine it's not suitable for roads (or allowed on cycle paths) - so far so good, the speed seems about right for pavements.
I'm not clear on what the use-case of the class 3 (8mph) machines actually is - 8mph is neither here not there. I can see a good case for 12mph and permission to use cycle paths.