And thats probably the point, in the absense of any official ban from either regulation or operation manuals, the Dacon Scoop is an approved rescue method (by whoever regulates this - HSE?) and so it comes down to personal opinion. If rescue is said to be available on the offshore weather report, then the flight is permitted depart.
However, some will refuse based on dacon scoop being the only available method, others will fly. Sometimes this will be on principal as above, or others will add discretionary safety buffers depending on conditions, e.g. ARA + Dacon scoop no, VFR and Dacon scoop OK as a very basic example.
So as a rescue provider you say yes or no depending on your contracts, requirements and regulations, you can or cannot offer compliant rescue mothods, and if the sea state, as per the met office model (not offshore reports) is less than 6m significant all the way to and from the platform, you may, or may not get a flight if dacon scoop is the only usable method.