Add 'all layers' option.
Dustball
Say you wanted to move or resize a doodle or a drawing to another part of the canvas, and it uses multiple layers. it would be a pain to use the lasso tool on each individual layer, and it might not line up right and you'd have to waste extra time fixing it. An 'all layers' feature would be useful for this, similar to the one in Ibis Paint.
Breadclip
This won't work if you only want a small group of layers moved, but I can usually work my way around this limitation by using the resize canvas tool. When using that, I can drag the canvas borders so that my drawing is more centered. Hope this helps!