If you like it and it is your thing, go for it. It is job assurance.
I’m ap/cp/fp but did damned little fp since the late 80’s.
It was not possible for me to do hospital ap/cp and keep on with the fp.
Phew, got an offer from my existing applications--didn't have to start a whole bunch of new apps. For future readers, here's the ACGME fellowship search page: ACGME - Accreditation Data System (ADS)