Hi Steve,
We are aware of the gap between the design stage and developing either components or screens with OutSystems, based on those design assets. This is something we're actively working, but at the moment there is no automation for this process.
However, there are a few ways to speed up the process. As Cristiana mentioned, OutSystems UI provides a solid base of UI patterns (or components) that are easy to customize to your UI needs, and a Sketch file with all the UI patterns, so the design team can speed up that process.
It is possible to import SVG files, but I'm not sure if what would allow to import a UI component, they would be treated as regular images.
I hope this helps,
My regards