I am pretty sure that would require JS, which I thought is something they deliberately try to avoid.

I did something else that didn't need JS - the first tab becomes a button pointing to "write" and moved the "skip to content" to the second tab. So the workflow is "tab -> enter" takes you to write. Hope this helps!

turns out there is accesskeyMDN Web Docsaccesskey HTML global attribute - HTML | MDNThe accesskey global attribute provides a hint for generating a keyboard shortcut for the current element. The attribute value must consist of a single printable character (which includes accented and other characters that can be generated by the keyboard). so for now ‘w’ works for jumping right to ‘write’ and ‘p’ for posting when you’re there. Can add more if needed. They need modifier key(s) in front (Alt on Chrome, Control+Option on Safari), etc (they’re documented in the link above).