Canvas drag handles don't stay centered when scaling

Hello @Marius and @StrangeTech,

This has been fixed in for the iFrame mode.

Unfortunately, due to the fact that we have little to no control on the actual container elements controlled by Gutenberg, the non-iFrame mode makes it impossible for us to alter them accordingly when scaling > 100%.
The scaling handles will not be visible depending on the scrollbar position, but the scaling bars are still accessible and usable when hovering on the sides of the resizable canvas.

If you run into any trouble, please don’t hesitate to let me know by replying to this thread.