Reminds me of the phrase:
"I might be a little bit pregnant"
That's an interesting point and makes me think about the degrees of non-compliance.
Pregnancy is an absolute condition. It's a yes or no situation, and if you cross the line from one to the other, there will be life-changing consequences.
With an e-bike, the condition is still absolute, but we have degrees of non-compliance and very low risk of consequences, but the risk goes up with the degree of non-complance.
Suppose a guy buys his EN15194 certified Oxygen Emate on the CTW scheme. When he rides it home, he finds the cutting in and out at 15 mph annoying, so he finds out how to hack the display software and increases the cut-off to 17mph, where it's a lot smoother.
Or the guy that buys a compliant bike and has trouble with his brake cut-offs, so he disconnects them.
Then there's the guy that buys a compliant Kalkhoff Aggattu. He finds out that with some simple jiggery pokery, you can adjust it to much more power and 24mph top speed, or the Ezee bike owner that pulls apart his speed restriction wires.
What about the guy that adds an Ebay DC/DC converter to run his lights. This will also certainly make his bike non-compliant. Fitting virtually any lights renders your bike non-compliant.
In summary, if we use the pregnancy test, I bet the majority of forum members will find themselves on the wrong side of the line, so the next question is how far over the line is acceptable? Non compliance is illegal whether it means fitting a light from your local cycle shop or a dongle to increase your bike's speed.