Resizing a drawing in shift and trace edit mode doesn't work as expected (center point not correct)

[DarrenTAnims]

Issue Summary

After selecting a drawing to change, I want to resize it, it doesn't work as you'd expect.

Screenshot or Video Reference

Steps to Reproduce

Draw 2 drawings in frames 1 & 2. Insert a blank between them, so that the drawings are now on frames 1 & 3.
In the menu, press View > Shift and Trace
then View > Edit Shift
Try to resize a drawing and it resizes around the center point of the screen, not the bounding boxed object as you would expect (and as happens using the standard Select tool).
So if you move the center point (the little circle) inside the bounding box, it seems to conflict and resize from the centre point of the screen and also the bounding box.

Expected Results

On selecting the image to edit, I'd expect the centre point to be in the centre of the bounding box and if I moved the centre point, I'd expect the resizing to occur around that point.

Actual Results

The resizing occurs about the centre of the screen when you first start, but if you move this point, the resizing goes a bit mad, working, it seems, alternately from the centre of the screen AND the new position of the centre point.

System Information

Using the nightly build from:
https://github.com/opentoonz/opentoonz_nightlies/releases/tag/nightly_98926de9b60802499ab899617149d6ffe527b3d8

[ghost]

This is still an issue with vector images.