Amending remote PR could be a killer feature for Gitless. gl init https://github.com/lxc/lxd/pull/3509 could clone https://github.com/lxc/lxd and checkout lxc/lxd#3509 in a single operation. Right now it is not possible (see #141). The possible workflow is this:

gl init https://github.com/lxc/lxd
# install some scripts
git pr 3509
# find out the name of PR repo and branch
gl remote -c patches git@github.com:techtonik/lxd.git
git fetch patches
git checkout patch-3
# do the stuff
git push