Motion blur on a Paint Node

Greetings, in order to get motion blur to show up on Paint Node strokes, do I need to:

1, Create Roto Node shapes with motion blur checked ON, then
2. Hook the Roto into a Paint Node, and just paint using the shapes with ‘Obey Alpha’ check ON for the shapes

or is there an alternate/better way?

Thanks!!

This is the preferred method.

OK thanks!