Can you be more specific?
What do you mean with "it works"?
Which command did you assign for textedit protocol?
Yesterday I read a similar answer and installed RVDefaultApp. Now I can set which application should open textedit:// URIs.
However I cannot set the text editor directly, as the text editor cannot handle this protocol.
I guess I should use lilypond-invoke-editor but, as I've already reported, I could not make it work on either Mac or Windows.
It looks like it's the last step to get what I want.