While California absolutely is overzealous in looking at people who leave the state, it's also reality that plenty of people don't really leave or blur the line

While California absolutely is overzealous in looking at people who leave the state, it's also reality that plenty of people don't really leave or blur the lines to the point where there's a legitimate question as to their residency. If you're going to leave California, leave. Don't keep a California address, tell clients you're based in California, come back all the time to do business, etc.