I searched and found nothing on drawing polygons. I see that it's possible to draw rectangles and lines, ideally with args.outputs.sprites, so they are all batched for the render update, but is there anything for drawing polygons with 5+ vertices?

I didn't manage to find on the docs what are all the accepted path symbols (:pixel, :solid, :line) for the sprites primitive either, is it only those 3?

Triangles api can be used to creat polygons. Example of creating a circle: https://docs.dragonruby.org/#/samples/ui-controls?id=radial-menu-mainrb