Yeah why wait. Shut down Angelflight, require AOCs for skydiving, ground RA. That one incident won't happen if nothing is flying. V1 you don't work for CASA by any chance?
Where I have flown for jumpers ATC advises if there is incoming conflicting traffic and if it is not resolved, the drop is cancelled. 3 min, drop complete calls are made on area and CTAF, in addition there is a company ground crew that checks for traffic and gives clearance.
With regard to the Amsterdam conditions, it's not that much different to The st kilda ops if you think about it. Minimum cloud base for parachute ops is around 4000', above CTA. ATC controls traffic above that where parachutist might be in cloud. And do you think that if a plane was flying towards a tandem, the instructor won't steer away?