You inspired me to write my own. Here is a 9-line shell script version of git-peak: https://git.sr.ht/~alexdavid/dotfiles/tree/master/bin/git-pe...
It doesn't do any fancy tarball magic for Github links, but the shallow clone works fast enough for me - sub 3s on modestly sized repos (especially on non-github repos since github is fairly slow to clone/push/pull).