Why is there no 'Downgrade to...' options in the popup menu on lines?

[G.M.]

There's a very useful tool: "Upgrade to Polyline/Bezierline".

It allows users that have created a single segment line, to add a segment to get around an object that would come across the line.

Unfortunately, if the user draws a line, then selects this option by error, there is no way of "Downgrading to" a single segment line, apart destroying the polyline and re-creating a fresh new single segment line.

I understand that "Downgrading" is not easy as information is lost and managing that (and related user new interactions) might be too much to pain for the developers for the utility of the new service.

I think an option solve this problem could be to completely get rid of this whole idea of "Up/Downgrading to", and simply always allow the user to Add/Remove corners/controls.
- If a corner is added => transparently switch to Polyline
- If a control is added => transparently switch to Bezier
- If there is only 1 segment/control and it is removed => transparently switch to single segment line
Wouldn't that gretly simplify the user experience at the expense of a very low quantity of code to add?