Actuator Rattle in Sequential

Folks,

Apologies for bringing this up again, previous threads don't give much of a clue...

My EGCV actuator rattles very loudly in sequential mode. I have ETTC and have to keep it in parallel around town, or it sounds like I have a nest of rattlesnakes under my bonnet when I lift off the throttle.

I ran the hose TTC mod before the ETTC mod was done, and the actuator started to rattle on tickover after a couple of months of hose TTC - have a buggered it up by leaving it doing redundant for a while?

Now, with ETTC, it doesn't rattle in parallel but is unbearable in sequential... if I hit boost, the rattle goes only to reappear soon after.

Questions:

1) Seems to me I have a boost leak somewhere that is causing the rattle, is this possible? Could it be the pressure tank?

2) Can I stop the rattle by lashing up the bars going into the actuator?

3) If the actuator is knackered, is it worth replacing it?

Thanks.