Helical features are supported in the latest Solvespace release (3.0pre3). There has been some discussion of how chamfers, fillets, and draft angles might work, but the concensus has been that they would be tricky to add, and are not a priority for release 3.0.
It's a fantastic platform though and I encourage all engineering/CAD nerds to try it out. It bridges the gap between writing OpenSCAD and using a full fledged CAD software perfectly.