I want to have small caps in my fonts with both uppercase and lowercase names ("X.sc and x.sc) and I want the lowercase versions to be built of components of the uppercase versions. Do I need to write a script to build them or can I just dump a list of expressions into generate the new glyphs like I can in Fontlab?
For now, you need to write a script. I will have a look the generate Glyphs command.
I’ve written scripts for that. Look for the Smallcaps scripts in my Github repository. They assume an x.smcp/X.c2sc naming scheme, but you can adapt the Python code to your liking.