This is indeed a very confusing issue to which the CAA has not been very clear on. We have recently had two separate customers come to us for exactly this and both got told opposite information from the CAA themselves. The good thing is though that the CAA have backtracked on their decision not to accept other ICAO IRs, which otherwise would have caused huge problems for many pilots flying in other countries or other licences.
In your particular case, What licence are you expecting to fly on? If you do not hold another licence and intend to fly on your EASA licence, any endorsements must be EASA approved or will not be valid. If on the other hand, you get a TR or another ICAO licence, then yes after some experience on type, all you have to do is sit an LPC with a EASA approved examiner and simulator. This will also cost a small fortune so if you have intentions to fly on your EASA licence, its best to do an EASA TR to save the lengthy paperwork process and have peace of mind.