on the subject of digitizing graphs I have enjoyed using https://graph2table.com/ - often it spits out a .csv file with very little fuss
Yeah, but the question is if it’s worth all the effort in this case, when it can be also sufficiently well meshed with tetras (of course, using dense local refinement), and there’s an option to use submodeling too.
I’ve also found this: https://labplot.org/
It’s a much bigger open-source software, but it seems to have a decent plot digitizer too. I’m sure there are other interesting offline solutions as well - I’m not a fan of the online ones personally.