Yes. My own experience agrees that bunching in specs areas is really bad, much worse than normal carriageways.
I suspect this is mostly due to those who occupy the overtaking lanes who believe they are doing everyone else a favour by 'being a pacecar', that is not letting other pass and preventing from getting caught by the cameras, but in reality they are actually in ignorant bliss that their speedo is way overreading.
The number of times I’ve seen L2/L3 numpties remain there, not overtaking, who are doing ~40 (GPS reading) in a specs 50 limit...
It is inevitable that other drivers, who know they are entitled to be able to travel faster, will get closer and invariably tailgate (not necessarily on purpose); that cant be good for safety.
Now it could be argued that it's not the lane-hogger’s (good intent or otherwise) fault that drivers bunch up too close behind them, but they
are encouraging it by their inappropriate use of lanes. The sooner everyone realises they shouldn’t be enforcing the roads, and applying the lane discipline required of them, the better.
I had a lane-hogger argument with my brother last week. He didn't see anything wrong with doing it; he didn't know L2, L3 etc are overtaking lanes and that drivers should keep left when safe and appropriate. I had to show him the Highway Code to convince him (which BTW did the trick
).