Hi,
A cool Addition would be a Artboard-like functionality from Affinity Photo and Designer.
On Document creation there is a option of to use an Artboard. In the Document itself the Image can be created and edited normally. At any time its possible to copy/paste the whole Artboard and keep working on the copy while keeping the other as reference or as different version of the image.
(Screenshot from Affinity Designer)
The Blue and Black Curve are the same just changed the colour in the 2nd Artboard and added another Curve.
Not sure how feasible it would to add this to PixiEditor