I'm not too sure about the paper quality/weight/foldability tradeoff, but I appreciate the fact that it's really light and I can just fold it in half and stuff it into my inside jacket pocket and go out and read it over coffee.
It might depend on the CI process. If the CI is only run on the tip of the branch being merged, then the PR should squashed, otherwise if a rollback it required, it would be possible to rollback to a commit that was not tested by CI. Unless there is a list of 'known good commits' somewhere.