Earlier this month the State Board of Forestry & Fire Protection held an online meeting to cover the proposed rules for Zone0.
You can watch a recording of the meeting here:
https://calfire.app.box.com/s/0bzo7l3due5vdhvlpt7wdezj1pgnp5ah
I highly recommend you watch the presentation portion of the meeting as it covers the rationale for the proposed rules.
Another workshop/meeting for the proposed rules is scheduled for April 7th and the Board is seeking feedback for several items.
A link to signup for the meeting plus the current rule draft can be found here:
https://bof.fire.ca.gov/projects-and-programs/defensible-space-zones-0-1-2/
Board of Forestry & Fire Protection Zone Zero