Just refusing the test with 0 DUIs is a mandatory license suspension (even if you are not convicted of a DUI), while you can have multiple DUIs without license suspension.
https://leginfo.legislature.ca.gov/faces/codes_displayText.x....
California's DMV will allow people with a suspended license to drive after they've installed an IID in their vehicle, so most lawyers' websites list that as a penalty instead of a 6 month license suspension.