Redirected from a former request, which was solved.
I found out that the polygonal selection tool in Clip Studio Paint creates nodes, clicking on a node during selection removes it and you can drag them as well.
@AhabGreybeard told me about several ways in which selections can be edited and converted in Krita.
The big diiference however is that CSP can do this during the selection process making the tool very versatile.
From my own experience and from what I have seen this is especially useful for comic book coloring and rendering.