It's not unusual for more static play on drivers side rebound spring Perry, especially if car is driven mainly solo, and due to main spring sag.
It needs to be avoided on either side though to avoid excess rebound suspension movement which equates to less comfortable ride and excessive roll.
I don't think you can blaim the garage who replaced king pins for this condition although maybe they could have made you aware. Cures are new spring set, shims or best of all the SSL RS front kit which is fully adjustable and so can compensate for spring sag over time.
With either solution the aim is to just have zero play static in rebound springs such that it does not compromise main spring rate under initial compression.
