I believe that if you complete the MECIR, that you can also have your PIFR signed off in your log book as well at the same time (just make sure your testing officer signs off all the aids that you can fly with for the PIFR as well).
This may help once your MECIR lapses. You will still have access to IFR flight under the private IFR rules. Plus the added experience of obtaining the MECIR can't be a bad thing!
Defiant.