This is why, like
@I like Skol I make damn sure I stick to the rules of the road because cyclists
are viewed as a homogenous group by some and if I can do just a little bit to show that cyclists don't cycle in a rubbish way that has to be a positive thing
But exceeding the speed limit on a bike
is still sticking to the rules of the road. Now, I've been known to jump the odd traffic light when I've come to the conclusion that they're not going to change, but by its very nature that's unlikely to be seen (a car behind will change them, for instance).
So it's fair to say that I'm not a stickler for the rules - equally, just because you're allowed to do something, doesn't make it prudent. But, like overtaking, if it's safe, legal, and makes progress, then go for it.
If doing 40 mph in a 30 limit rather than 30 mph means that you aren't being squashed against the kerb by motorists obsessed with overtaking you, because bike, thus allowing you to ride in primary++ and therefore giving far more reaction time and space to any pedestrians walking out, it may well even end up being safer than keeping to the limit. Again, not necessarily, but that comes down to reading the road, not the number on a sign.
For instance, coming down Cumnor Hill into Oxford, the speed limit drops from 40 to 30 mph, and I'd generally stay doing closer to 40. The biggest hazard was the junction with Eynsham Road, where drivers would inevitably decide that bike=slow, so pull out on you.
By doing 40 mph, you could easily pull into the right hand lane and overtake any dozy twit, comfortable in the knowledge that you yourself were not being overtaken, particularly given the speed camera at that location
Sadly I never saw the blasted thing flash me. 🤬
I would put money on you being in more danger if you were doing 30 rather than 40 there.