There is currently no way handle multiple icons at the same time. I mean you could still make a copy of each icon by just dragging them to a new folder in finder. We have multi-selection handling in our roadmap. Follow us on @svgsus on twitter and I'll make sure to ping you once we implemented it.

I've cleaned thousands of SVGs with: https://github.com/svg/svgo

  npm install -g svgo
  svgo -f /path/to/svg/files