Yes. That’s pretty much how it is. I would do the typesetting in Glyphs, then import the PDF into Illustrator.
You could try Type3, but I bet you will run into problems with the SVG then. Also, I doubt recent AI versions support it.
Or do it with a design hack: Close all your paths with a node you put 100 units above everything else, then typeset in AI and convert to paths. It shouldn’t be too hard to just select those top connector nodes and delete them in one step.
PS: If you do develop your own font format, please write a filetype plugin for Glyphs 