With regards the change of competent authority, the CAA are stating that the processing time they try to meet is 10 days. Wether this is the time it takes for them to log your application or the actual time in working days to be ready to issue the applicant with a UK issued part FCL , i dont know. Unlikely to be 10 days total, as it relies on your issuing authority pulling their finger out and sending your documents to the CAA for processing. Anyone actually done tnis?
Therefore one could apply , and then change your none EASA licence to a uk issued one. If you are holding a none easa rating, eg B777 or B787 and are restricted to aircraft registered say in UAE, you will have to remove the restriction first, as the CAA dont as yet allow this ( any change here?). again this will take a few months are independant examiners are full of expats renewing their licences
