They are supplemental right now - you can use the Printer without the other two and same goes for the other two.
The assets for both workshops are included in the Printer but as Godot’s resource files, not as raw PNGs. Once I figure out a good way to have the Printer reading stuff on the fly both Workshops will become obsolete - since you will have access to all its content straight from the Printer. There is also the plus that with reading stuff on the fly you will also be able to add your own files to the Printer, making it even more flexible.