When I got my reMarkable two years ago I tried their app’s vector output: it was awful, because they were using completely the wrong technique: taking intersecting paths, taking the union, and then simplifying the path very lossily, which particularly ruins intersections because of the union step.

It’s possible they’ve improved the technique now, but I’d be a little surprised if they have, given that it amounts to throwing away the entire thing and starting from scratch.

There are a few open-source libraries to convert the .rm format to SVG. None are good for anything but the fineliner. I’ve written the closest one to decent for tools like the pen (though I haven’t got round to publishing it), but it still lacks the texture (pretty much unavoidable) and is thus never going to be excellent. SVG just lacks the necessary primitives.