It seems this 'situation' is always a surprise to those who may not have experienced it before.
At a licensed airport ATC would normally require landing traffic to be separated by several minutes from a large Rotary movement for very good reasons.
When we operated Islanders to St Marys IOS back along, the other main user was the S61 from PZ which put out a hefty rotary wash and was best kept at a safe distance (or upwind of it).
In fact St Marys ATC would not allow an approach by fixed wing for several minutes to keep matters safe.
We would sometimes 'encounter' the S61 effect enroute and that was enough to keep you 'aware' of a regime that is best avoided.