J & L cuts without using the mouse

Is it possible to do J and L cuts without using the mouse (so only keyboard or Speed Editor) in Resolve?

(on windows, by default) select a cut with linked audio with v, cycle trough audio only/video only/video+audio with alt+u. trim with . or ,

unfortunately you have to leave the speed editor/cut page workflow

Yes, but just to clarify, you certainly can do J/L cuts (and more) on the edit page using the speed editor.

Interestingly, the speed editor keypress functions (e.g. TRIM OUT / TRIM IN / ROLL) can be used simultaneously with keyboard shortcuts (such as the ones Rick mentioned, for example) to enable better selection and control of edit points for trimming and adding transitions.