I have only just opened this thread and have read it through, and I think it has got away from the nub of the issue as I see it. If you are flying IFR (IMC or not) you must have the equipment and skills to allow you to complete that flight safely. Since the CAA does not yet see fit to agree to the use of GPS as a primary navigation aid (which is wahat the original question was suggesting) then you need to be competent in the interpretation and operation of those navaids which are permitted. Much discussion has been had about NDB holding and I personally cannot see what all the fuss is about. If you go and practice them (on your PC if available) after perhaps a briefing from someone who knows and understands them, I bet that you will soon get them cracked. Look elsewhere in this forum for info on how to calculate drift easily, and you will be home and dry.
I worry about those who suggest that it's OK to go flying with less than the necessary skills or equipment because they can always divert to somewhere those are not needed. The point has already been admirably made about the potential hazards of that policy. Surely you should not be contemplating going flyin with the knowledge that your skills which ultimately your life may depend upon are not up to scratch. It's like saying that your crosswind landings are crap but it doesn't matter because you will only fly to airfields with an into-wind runway. What about when there isn't one or you haven't got enough fuel to get to it?
ILS and VOR and Radar are very reliable, but they DO fail, and if your lifesaver is an NDB hold and approach, then I would think to learn how to fly one is a small price to pay. It's costing you enough to be up there anyway, so why not make sure you can do the job properly.
By the way, I have also had to fly an NDB hold and approach for real when I had expected a radar vectored ILS. It does happen.
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"Take-off is optional, Landing is mandatory"