I use scanservejs since at least one year and can confirm it’s the best.

As for printing, I went down the same rabbit hole and had zero luck. Seems such a stupid thing yet nobody created such a service, except for a couple of commercial ones.

So yeah, if you find something …

By the way, probably creating a simple web interface that accepts uploads and pipe to lpr is pretty easy to do, but I didn’t got around to do it. Printing feels… Outdated. And printing from computer or android is so easy anyway that probably useless.