The boost capsule or pump fuel adjustments will not account for grey/white smoke. black smoke yes. you may find without excess fuel at low rpm the turbo lag will be really bad, and it may not get up on boost at all without some "coal on the fire" white is definetley unburnt fuel/oil. if all is well with the engine and it over fuels it could make black smoke as the fuel will burn, if its not burning its because its in the ong place or at the wong time!
No amount of max fuel adjustment(fuel stop)will make any difference at tickover, the engine is off load and the fuel is entirely controlled by the govenor. the only time the fuel stop will make any differenge is when the throttle is on the bulkhead and before the engine reaches governed speed.
What happens to the smoke if you leave it revving at 2k in neutral?
is it better or worse? if its worse and the engine sounds a bit wooly it could well be timing.
you need to spill time the pump if its an inline pump, or make sure its locked at injection point if its a rotary pump or marked at injection point.
a few degrees of advance wont hurt, and may prove a point as to whether its fuel timing related or not. Worth checking the turbo tract for lube oil too, could be turbo seals or a blocked breather forcing oil into the intake?
We had a ford engined lorry, the smoke when it was cold would make your eyes water! however when warm it was fine. there was nothing wrong with that in particular and it didnt use much oil unfortunately being a DI and turbo it took a while to warm up. they were notorious for it as were the perkins 500 engines(prima) so smokey at light load you cant really use them in a river boat