Note Pinta was only ever a port of the engine, Pinta's UI is a from-scratch Gtk# clone. Given the compelling reason to use Paint.NET was arguably the UI, that's a pretty big drawback.

The UI is pretty similar. It's very intuitive for someone used to Paint.NET. Pinta definitely satisfies my desire for Paint.NET on Linux.

I have tried to use Pinta at several independent points in time over the past 10+ years, and every time I have tried it, it has been so buggy as to be practically unusable.

It's a shame. It would be the perfect application for my basic image editing needs, if only I could actually rely on it to work.

These days, I just use Krita. It's on the heavier side, but functionally, it does what I need.