I use Glyphs over illustrator a lot when working on branding, would you ever consider creating a pasteboard within Glyphs that would act as a sort of “sketch board” where you could treat it like an Illustrator file, but just one giant artboard.
I know this is far fetched, but I also think it would be helpful for quick tests while working on type.
I wouldn’t mind this as a feature either, but you can set this up in a separate file pretty easily too. first create a new file, change the UPM to something high like 10,000. delete the font metrics except for ascender and baseline. delete all the glyphs. add a new glyph called “artboard” and set its width to 10,000 and now you’ve got a nice big square artboard to work on