The latest news on this front comes from a really interesting article at Ballot Access News written by the widely-respected election expert and advocate for third party/independent ballot access Richard Winger:

Joseph Hero filed to run for a local office in Lake County, Indiana, earlier this year. He is a Republican and the office is partisan, so he filed in the Republican primary. However, in 2015, the Republican Party had “banned” him for ten years because he had supported two independent candidates for local office. The Lake County Election Board therefore wouldn’t let him run in the 2019 primary. On August 26, he sued the board, arguing that the board had no right to exclude him. There is nothing in the Indiana election code that permits a party to “ban” people from running in the party primary.

The case is Hero v Lake County Election Board, n.d., 2:19cv-319. Here is his Complaint. He does not expect the case to affect the 2019 election.