Thanks for the detailed reply davie7ee. I'm trying to study for the EASA CPL exams at the minute, as I have FAA commercial, so am exempt the groundschool/classroom bit and can just self study and take the exams - which I didn't know I could do until recently. Only small problem being I'll have to do them all again plus a little bit more to get ATPL theory should I need that, which I probably will in future to have any real hope of a job in the EU - although on paper a EASA CPL/MEIR should suffice, and I'll just be stuck right seat for the rest of my life, never getting a command.
I did the FI stuff, coming from FAA CFI/II AGI IGI, and have been working full-time as an FI for well over a year now... I was able to get that using the route you mentioned, logging something like 4.5 hours flying (including test) and a bit of ground. I should mention I'd also held the EASA CRI rating for over a year prior, so I think some of that helped, as it wasn't based purely on my FAA credentials. So all the talk of this 15 hours flight and 30 ground is nonsense, because as you correctly point out, the ATO can decide on a reduction which the CAA then have to accept - which is great info for any other foreign FIs trying to get into the EASA system. Fortunately the thing that works for me is the allowance of paid flight instruction on a PPL, and that I can teach students towards LAPL/NPPL without having EASA CPL theoretical knowledge passes. So there are some positives, and you can make things work if you do your research and have a good ATO that will back you up and not force you into flying for 15 hours!
Just gets my back up that we have such a stupid system where ICAO qualified people have to jump through so many hoops and get around all the beurocracy and protectionism to do the things that they are more than capable of doing, if only they had different writing stamped on their licences/certificates and certain registrations on their aircraft.