Agisoft allows vector drawings but still in a very limited manner if compared with Global Mapper or any CAD/GIS (no layers, no symbology, no annotations, many other noes). I hope the Agisoft Team will improve the built-in CAD capabilities in the future, so it's time for us to encourage them in that sense.
In the meanwhile I'd strongly recommend Virtual Surveyor as one of the best Photoscan companion if 2,5D feature collection is okay for your needs in terms of drawing.
Best