As pointed out in the answer to PDF file size with LuaLaTeX vs XeLaTeX, the difference between using Type 1 and Type 1C fonts in two documents made a big difference in file size.
File size is important in the PDF files I'm working with. So my question is can you force LuaLaTeX to embed a Type 1C font instead of Type 1? This is something XeLaTeX can do (and in the case of the question cited above, did automatically).
The font I'm working with is Gill Sans MT (I believe it comes with Adobe CS). While I'm not opposed to changing fonts, I'd still like to know how LuaLaTeX decides how to embed fonts and how it can be changed.