Playback technique editor

Hi!
I’ve started experimenting a bit with the Playback technique editor in Dorico. The first thing that strikes me is that there is no undo function…

The second thing is that the zoom function doesn’t work very well - things end up outside the workspace.

I don’t think the above mentioned things are my fault, but maybe the following:

I’m trying to make a new PBT based on an old one. I add a number and remove the previous one. What’s so frustrating is that when I move the new number, the previously inserted objects also move. I see that they are linked with blue lines and arrows but I can’t figure out how to move all the objects individually. Can anyone recommend a good reference besides the Dorico manual?