FCL.625.A IR(A) - Revalidation
(a) Revalidation.
To revalidate an IR(A) , applicants shall:
(1) hold the relevant class or type rating, unless the IR revalidation is combined with the renewal of the relevant class or type rating;
To revalidate the ME-IR you must hold a valid MEP. Yes, you can revalidate the ME-IR then let the MEP lapse, but gone are the days where you could revalidate the ME-IR while the MEP was expired. That went in 2019.
Yes, next year you could revalidate the ME-IR and renew the MEP at the same time in the aircraft.
All expiry dates are to the end of the month, so your IR will be revalidated to the end of the month + 1 year. What is written against the expiry date now? It should always be the last day of the respective month.
You can revalidate the ME-IR and SE-IR at the same time, as long as you hold the SEP (land).