Hi 'Hook'
I, unfortunately, don't have any answers for you on this one. Only to say that I have a one year old 4/4 and the seat adjustment on mine are really quite tight (both seats).
I would assume that the runners on my seats would be lubricated from new so if they can be adjusted to run a bit easier, I too would be very interested to hear from anyone with a solution.
Cheers,
David