I see there is a new AD out concerning the affected shafts. Apart from putting the M'ARMS download interval up to 4 hrs, there are some rather odd other constraints.
The AD only applies to helicopters operated over water at night or in IMC.
If the M'ARMS is unservicable, the heli can still be operated over water but has to be placarded "Day VFR only for flights over water".
Is it just me, or is it pointless to make the differentiator flight in IMC, rather than anything relating to survivability following ditching. If flying in IMC over flat water, this does not impede safe ditching (surface fog excepted). But a wild sea state certainly does.
Similarly if flying in mountainous terrain with cloud down to the surface, you would be vey badly placed to have to make an emergency landing, but the AD doesn't care about that.
Is there anyone in EASA who understands anything about helicopter ops?