I ran into trouble when trying to create a new project from my own template via :local/root: deps-new could not find the template file, maybe because there was a space in the path. When displaying the error, the space was displayed as %20 in the path. Doing the same command using :git/sha made it work.
It's late here, I can provide a repro tomorrow if needed.
My template, for repro: https://github.com/green-coder/vrac-app-template
I agree that spaces are a bad idea. I wrote a repro in github in case you want to make a fix. It's not blocking me, btw.