The best tech I can name is Benny Rodriguez in Alameda.
https://www.bjrguitars.com/
Kevin Robertson is my usual go-to guy in Vallejo. Super ethical will often charge me less if the work was less than expected. He builds and restores guitars, but mostly works as a tech when not at his regular job at Mesa Boogie.
http://krguitars.com/KRGuitars/Home.html