Editing sketches in Revit always boils down to erasing old elements and adding new ones. Why not provide a similar functionality as polyline editing in AutoCAD. It took what feels like forever to get the add node or convert to arc/line functionality. There is some space left in sketch edit mode which could be used for a new method to morph a line into an arc or a spline into lne fragments. It would also be helpful if the add node feature provided for splines were added to all other entities as well.
(Tested this in Revit 2023)