EDIT: problem solved. I saved the light setup as a ZLI file, and then recorded loading it into the scene in a Zscript and added that to the DefaultZScript. Hopefully this will be useful to others.
I’ve set up my lights the way I like for sculpting, with a bluish key light and a yellowish fill light. But I can’t find any way to save this setup so that it is applied when I create a new file.
I have a lot of other settings for materials and such, which I have put into the DefaultZScript.txt file, and that works fine. But for some reason the Zscript doesn’t record some of the necessary information for lights in particular.