Does taxpayer intend to return to CA? Is there a CA home owned?
We had a lot of this when GM and Ford closed and TP moved. I had some clients file as CA residents for years, even when the TP moved to MO, but worked in KS and the spouse stayed in CA. There were several credit paid to other state contortions to go through. See L on page 9 of https://www.ftb.ca.gov/forms/2016/16_1031.pdf