There's two kinds of "free service" on the internet. There's the Facebook / Google kind of free, where the herd of non-paying users is being aggressively monet

There's two kinds of "free service" on the internet. There's the Facebook / Google kind of free, where the herd of non-paying users is being aggressively monetised in other ways by a very profitable business. It's perfectly reasonable to expect this kind of free service to jump through the GDPR hoops as just another cost of doing business. This is the other kind of free, where it genuinely is being done out of interests sake as a public service, like guerilla gardeners. In this case, it's perfectly reasonable to say that you got into this because you're interested in solving the technical challenges, not because you enjoy wading through bureaucratic rules, and decide to stop offering that free service in the EU because the fun has gone out of it. Probably you're completely right about how easy complying would actually be, and in that case you could certainly take this code and run your own push server that serves EU clients.