With respect some of the problems are of our own making and there are non worse than the British Pilots.
The rules were not made with the intention of mixing and matching licences and ratings to achieve the results we often seek. This leads to a layer of complication that is not expected. The UK CAA have historically been one the most pragmatic of the European NAA's.
The rules are actually quite simple, if you want to fly something with differences that is on a European reg then you have to meet the requirements. In the case of Tailwheel, you do Tailwheel differences training and receive a logbook endorsement from an EASA FI(A). There is an allowance for the holder of an ICAO licence who has been trained and can show recency to be exempt from this requirement which is fair. However do you think it reasonable to go and train with an non EASA instructor to gain credit on an EASA licence and type?
Now there is a lot left to the discretion of the Instructor on the content of the differences training, so there is no reason why you could not do a quick flight and demonstrate to the Instructor competence as a tailwheel pilot and be signed off. Other differences may not even require a flight, for example if you have been flying a turbo charged engine, a ground session demonstrating the required knowledge may be all thats needed.
You have to think outside the box rather than having the usual British mentality of looking for blocks and problems where in reality none exist.
Having said all of that, I do think that there are flaws in Part FCL that need to be worked out, just as there were in JAR. As an example the requirements for renewing an SEP(Sea) changed in Part FCL so that you cant combine the SEP(Land) and SEP (Sea) ratings anymore, meant I had to haul my bum to Florida and spend 12hrs cruising around the Winterhaven Lakes. I have submitted a rule making proposal to change this back to the way it was.
My advice, read the CAP and the Part FCL documents and engage with the new system rather than kicking it.