A module file path can have spaces if you manually put quotation marks around it (in the “Load Library” text field). I’ve just tested it. It works. It will also appear with quotation marks in the netlist if you generate one.
The problem is not that it cannot have spaces, the problem is, when I use the GUI and the “Load Library” field (i.e. clicking on the “dot dot dot” symbol of it, so that a file chooser menu opens to choose the path), it will not automatically surround it by quotation marks, and will not remove the “.dll” from the path. I have to do that manually. That’s not a problem if I create the whole netlist manually, of course. It’s a GUI problem.