Arrowflyer,
Most of what you say is correct.
The key thing is the original poster does not currently hold an FI rating, they did not have a FI rating on the EASA license as of the 31/12/20, therefore as I understand new ratings added to an EASA license after transition would not be automatically transferred to the UK Part FCL license. The UK only recognises what is on the EASA license on and before the 31/12/2020.
They would need to check with the UK CAA first if the EASA FI course and EASA FI test will be accepted by the UK CAA for issuing a UK Part FCL FI. My understanding is the CAA may accept the training and test but it is not guarenteed.
Last edited by portsharbourflyer; 19th Aug 2021 at 17:33.