I'm certainly getting the impression that what's in the "air" is a deepening commercial pressure to relax the restrictions.
Just because an aircraft flew Dusseldorf to Amsterdam OK doesn't mean that airspace corridor is "clean" in this dymanic situation.
All I know is that every day there is a smattering of dust on cars the length & breadth of the UK - It's a question of safety v commercial pressure.
If the regs are relaxed & this is followed by a spate of Maydays then you can expect groundings & costly inspections fleet wide for an even longer period of time.
I think the forecast south westerlys on Friday, will be the only sure way to clear the air from Northern Europe.....except it will only be going somewhere else.