Consider porting to MyPaint engine
Description The addition of MyPaint engine will solve multiple filed issues: #1614, #854, #751 and may make the maintenance easier.
Additional context Both GNU Image Manipulation Program and Krita offer support for MyPaint brushes, allowing to use the same brushes in different applications.
I think it'd need some investigation to figure out how hard or easy it would be to integrate, since Pinta is in C# while this is a C library. (If anyone's interested in working on this, I'd recommend doing it as an add-in)
I don't know the technical details, but would the simpler route (potentially) be to add support for MyPaint brushes as GIMP and Krita* (sorry for the typo) have done, rather than adding a new dependency on an external library?