Actually, you can do pretty much anything in Styler at this point. You may need to do some "source modifications" in the stylesheet, but with APP now as a composition engine, you can take advantage of everything APP can do as well as everything that FOSI or FO can do from within Styler. (Well, you've got to pick a technology, but it's all there and possible.)
At PTC/User this year, Zarella was showing me that she'd created a to-spec UBL invoice using only Styler with no source edits. It's fully capable now.