Vote in the Primary then change your voter registration to another “Party”. Next year you can change back to Republican so you can vote in the Primary, then change from Republican once again.
The State accepts whatever word you write in the “Party” block. Make up a name or use “None”. That’s one way to show you don’t like the lack of respect for the voters.
Democrats can do the same thing. Change from Democrat after the Primary than change back to vote in the Primary.
Admittedly it’s a very small step but if enough voters do this in protest against the lack of respect for the voters by the party leaders the party bosses will notice and it’s better than going along with the rigged process. JFK’s sister once said: at least shake the bars of the cell to let them know you’re in here and you are against them.