ZBrushCentral

Dynamesh and projection problems

I’m having difficulties converting a reasonably complex mesh into a solid printable stl.
I cant share images as the project is under heavy Nda but it involves multiple sculpted elements be merged together into a compound curve. I’m connected them in cinema 4d and go zing into zbrush I then duplicate, Dynamesh to weld all objects and create one solid shape. I then project back the detail and decimate for printing. However I’m getting some weird rests when I re project! Mainly flat areas in places that should be shapes any ideas on how I could fix this or is there any easier way to create printable mesh? Can I just decimate for example?