So I've eliminated most IK's. I used to have a full lock from start to finish when masturbating and now (with a lot of concentration) can prevent that entirely, it's getting easier every time.

However, there is a specific IK which I cannot control. It feels like my anus rises inwards when I start masturbating and I can only push it out with an RK when I stop for a break. It is very localised and does not cause my penis to swell and there is no twitch on my BC muscle.

Do you think this is something I need to eliminate?

I haven't really noticed much of an improvement in how long I last during masturbation. I know when to ease off so in that sense I am in control, however I can't keep going for long without having to slow down or pay less attention to the head etc.

Any thoughts?