You're quite right, Martin. The seat 'pad' fits onto the grp seat 'box' and is opened by undoing a strap that fits over the seat, lifting the 'pad' by approx. an inch and then sliding it back. Works very well!
(BTW I also like our centre mounted throttle and in the 18 months we've had the boat it's never been 'knocked accidentally' by the passenger. It does mean the passenger can take control very easily if necessary.)
And, yeah, I know, everyone thinks their own set-up is best but Richard spent 2 years trying different makes/models/set-ups and drew up a 'wish list' before purchasing. Luckily for us, 'Blue Ice' ticked just about every box!