Filtering - if I were on a motorbike I would filter as far as was safe to do so. I wouldn't barge into the ASL, as I see bikers do in London, nor block the cycle lane. I would know that cyclists are more vulnerable since they don't have the same acceleration. The ability to filter is not the only reason to have a motorbike.
Secondly, if I were sat in the traffic unable to get to the front, but my machine can do 0 to 60 in a few seconds, frankly, it wouldn't bother me. Some motorbikes can accelerate faster than cars, and armed with that amount of power, would you need to get to the front?.
Funny thing about motorcycling. I see them being ridden at speed on motorways, often changing lanes at 70-80mph, which is far, far more risky than sitting in a jam. The faster you go, the proportionate the risk is. High speed is high risk etc. So why then, do motorcyclists suddenly feel 'at risk' when they come across a line of stationary traffic at 0mph?. By forcing their way into the ASL, they put cyclists at risk. Ever tried to get into the ASL and it's full of motorbikes?.
I was cut up badly last year by biker who entered the ASL behind me, moved over to the left and pulled alongside me (I am turning right, so occupy the centre of the ASL). He wasn't indicating, and when the lights changed, he roared ahead and....guess what?. The fool did a right turn from a left hand position. It was one of those wish-I -had-a-helmet-cam moments.