I had the idea to reuse assistant setup on various images, but unless the image is the same size as the original image it is not possible. The new assistant is scaled to the size of the original image.

Resizing would make assistants, a super neat tool to work on concepts as you could have several perspective setups depending on what you want to present.

Rotate and perspective transform, like the transform tool, would be nice additions.

I guess applying the calculations on the assistant control points its enough to make them transform. Holding a Key could make the handles for transformation appear or a GUI mode to make them transformable.

Simple select could work like this:
GUI button to lock all assistants as a group.

Or more complete selection:
Right click to select.
SHIFT + right click to add to selection
SHIFT + drag, draw a square, select all assistants inside square.

Reproducible: Always