Field Required the UK, as you know, adopted all EU law before exit day and amended it with the Aviation Safety Act, which effectively repeatedly deletes the terms 'EASA' and 'member state' and replaces them with 'UK CAA'. Thus it is bound by Article 8 of EU decision 1178/2011 which says that, absent a two way agreement between States, the UK can convert foreign licences giving, in the case of ATPLs, credit against approved training but requiring all 13 TK exams to be taken and an ATPL skills test on type. EASA is bound by their equivalent, which is now amended to Article 3 of something else - can't remember. This means that licence reciprocity needs either (i) a bilateral agreement between UK and EASA, which is apparently being pursued but even if successful may take years, or could be done in a day if there was political will or (ii) a change in the law on both sides of the Channel. Obviously (i) is easier, but depends entirely on the political will being there on both sides.