I've been using html2canvas for a long time in https://play.basketball-gm.com/ so I gave your library a try. It was much slower (I know your README has benchmarks saying the opposite so idk) and the result looked a lot worse.

html2canvas: https://i.imgur.com/zfSwNR1.png

snapdom: https://i.imgur.com/FxowTzp.png

Also I recommend putting the npm package name clearly in your README. I guess I don't really know what other people are doing these days, but I think most people are like me and consume packages like this from npm rather than a <script> tag.