Lemurian - you do have to hold the priority button. If you release within 40 seconds the other sidestick becomes live again.
Thanks. Shows how much I've used it !
I've only used it to confirm the "I have control ..." bit. I've never needed to de-activate the F/O's sidestick.
BEagle
my query concerned a take-over against an undesirable input from the other CM.
By keeping the button pressed, the CM who has taken over will maintain control - but needs to hold it for 40 sec to 'isolate' the other CM's sidestick.
Is that it?
Perfect !