One of the things I find difficult about Bubble is group management. Often, I will create an object but wish to move it to a different group without moving its position. In design applications, this is possible from the sidebar. Gif in Sketch below.
Implementation of this would allow powerful interactions and organization. Especially for apps made for mobile, where everything is state based on a single page, and the layers add up!
I used to find this a bit challenging, but so long as you use the menu items, you should have no problem moving / copying objects between groups. Don’t attempt this with keyboard shortcuts - those won’t work well.