So how would O&G or corporate crews conduct an IMC letdown to Blacksod at night with a 300' cloudbase?
With an appropriate approach profile to a suitably placed MAPt, according to minima appropriate for the role, equipment fit, and training of the crew. Subject (if applicable) to availability of suitable pre-planned weather alternates.
The point is that nobody outside the SAR world (and at least some within it, it seems) would even consider the approach profile taken by this flight, and if they had been given the APBSS chart they would have stored it in the VFR section of their flight bag if not the round file next to their desk. But because they could, they did.