If the benefit of service is in CA, there's good chance you're going to be required to file in CA

If you provide personal services and the benefit of that service is to a California customer, you may have a California income tax filing requirement.  The tax filing requirement may apply regardless of a physical presence in California.

"A second interested parties meeting is scheduled for June 16, 2017.  Staff will present draft language for the less controversial issues of the proposed amendments at the second IPM."

Click on link for more information.

https://www.ftb.ca.gov/professionals/taxnews/Editions/2017/May.shtml#Article01