I wonder how the apples developed by Etters would do there. He lived in Humboldt county. Most of his varieties have a long growing season.
You might consider looking into Alkmene.
I’m going to resurrect this old thread with some updated info on coastal apples. I’m zone 10a, same as the OP; and Sunset zone 17.
I just have one apple frankentree with 15 varieties grafted on, and not all of them are bearing yet. The original graft on the tree (planted in 2015) was Gravenstein, and I get excellent Gravensteins off it every year. Other varieties that bore fruit for the first time last year were Granny Smith, Jonalicious and Mollie’s Delicious. All of them were good. But the real standout was the Etter apple Pink Pearl, also bearing for the first time. The interior was a deep pink, the texture was perfectly crisp and juicy, and the taste was excellent with a hint of raspberry. I was really surprised, because usually this apple isn’t rated very highly. But I would almost have to say it was the best apple I have ever eaten.
So far the only varieties I’ve grafted on that have not performed well here are Kandil Sinap and Honeycrisp.
In the right climate, Pink Pearl is great. I look forward to it every year. Mott’s Pink is also very good here, slightly earlier and a bit more tart. PP is the better apple, to my mind, but Mott’s is worthy of a graft.
Kandil Sinap has performed poorly for me as well. I should take it out, but haven’t gotten around to it.