Anti-aliasing has been added to the Sketcher in the latest GIT checkin. A rough demo is at:

If anyone wants a static build to test, just let us know which distro and version. It is no trouble to create a build and testing would be appreciated. Soon there will be a Debian 9 and 10 static tar at: https://cinelerra-gg.org/download/testing

I agree and possibly would also like to implement presets of shapes,rotations and scaling (as in the mask tool).

Rotating and Scaling will be worked on (but not tomorrow on Christmas day). An attempt to add presets of shapes ended as a complete disaster as an attempt to port Mask presets was a totally different design. Decision was made to not add shapes because to make a square/rectangle/triangle and even a circle is trivial with just 3, 4, or 5 points (for a circle you just make a box using Line and then switch to Curve) while the programming time would be days.