Annotating OmniPlan

I don’t think OmniPlan provides a means to draw or annotate a Gantt chart, so I’m wondering if anyone has any suggestions for how best to do this? Do you just export your plan to some type of image format and then use a drawing program? Or is there a better way? Thanks!

You could export as PDF and annotate using a PDF software. It’s better than images, imo.