So I am curious, lets have a few postings of those flights that poster on here with an IMCR (IO540 you are banned from response!) have actually used there IMCR for in 'battle' over the last 6 months and what they have done to retain currency. I am interested only in IMCR holders not FAA pilots with an IMCR on the back of a proper IR.
This kind of survey (attempted by so many) unfortunately means nothing, without looking into what people fly (aircraft/equipment) and what kind of access arrangements they have, and of course time/money budgets.
THAT is the biggest limiting factor in pilot currency, not what kind of piece of paper they collected yonks ago.
I don't recall learning anything of relevance to actual instrument flight in the IR. But that could be because I had ~ 600hrs and about 100hrs IMC time (no AP) by the time I did it. Everything needed to fly Euro airways could easily be contained in a slightly modified IMCR syllabus. More than 15hrs would be needed but that's true for the IMCR in practice too.
The challenge would be finding instructors who can teach it out of personal experience (basically, no ATPL hour builders) and the punters would need to be wealthier too because once you starting doing real instrument flight from A to B it will get much more fun but rather expensive.
BTW there is no such thing as accurate flying of an NDB approach. Well, you could fly it accurately as far as the ADF instrument indication is concerned, but where the plane will actually be is another matter
I rarely file Eurocontrol over the UK and just fly on what might be the privileges of the IMCR, Class G. Keeping current is not a problem - one just has to get out there when one can. In this weather it's very hard unless one is unemployed or doesn't have to work for some other reason, yet can still afford to fly. Yesterday was a perfect flying day but that was a rare break.