I didn't really intend to open this can of worms, and have learned a lot that I didn't know! I just wonder what the punishment might be for such a transgression? If its anything like someone who is unlicensed, uninsured and driving a defective untaxed and untested vehicle.. £100 fine and a slap on the wrist!
the punishment isn't really the thing you should be worried about.
imagine if you're riding along at 10mph minding your own business, some guy driving along side you, overtakes you, but misjudges things slightly, causing him to clip your shoulder. You get knocked off, and your bike is a write off, he swerves and takes out 3 cars causing thousands of £s of damage to 4 cars and your bike.
Your bike will be crushed because its being illegally used on the road, so you've lost the money you invested in it. No come back.
You'll be chased by all the insurance companies because you riding the illegal vehicle will be used by them to claim that you caused the accident.
Plus the case will be the first one to involve an eBike, so it'll be splashed over all the press (cycling and transport) and will be held up as an example as to why eBikes should be banned, or treated like mopeds.
So yes, the £100.00 fine and a slap on the risk is one risk. But the implications of an incident could be massive you for as the individual involved, the shop that sold you the bike, and the industry.
Anyone who just thinks they are just "speeding" doesn't understand what they are doing, and the wider implications.