Equal, EqualRadius, PointOnObject sketch constraints

I was writing a compatibility script to use freecad to define sketches interactively and export them cadquery and I noticed that these three kinds of constraints are missing from cadquery sketch constraints. I couldn't think of any easy solution to circumvent this limitation when the sketch is defined in an **external program**. Is there any interest to implement them? I should have some time to work on them unless there is some technical reason not to.