It depends on what state you live in. PA is a closed primary state. Changing to an unaffiliated will exclude you from voting in the primaries. I always make a point to vote in primaries against any incumbent GOP’ers on principle. I have been lucky lately that there is usually a Constitutionalists challenger.
“Changing to an unaffiliated will exclude you from voting in the primaries.”
In federal primaries PA as a whole is excluded. The candidates are chosen well before has chance to cast a ballot.
I’m in Texas. We have caucuses after each primary election, but I think you get to vote in either party primary you want.