Ability to paint within a shape or send to Fresco while maintaining line quality.
In Fresco, I can freehand vector lines but cannot edit them like in Illustrator. In Illustrator my color/paint options are severely limited. Being able to paint or draw within a shape would be wonderful. If the two apps could share files I could have the best of both worlds.
(I tried exporting to a psd the loading in Fresco but it rasterized my lines.)