This is not what happens for me. I think you are being blinded by the fact that you know how to do things in a way that seems to work.
1. Open Leo with --init-docks. Workbook opens in the default layout which is not what I want. Create a new outline. Change the layout to mine. Close Leo without saving the new file. Reopen with --use-docks. Leo opens with workbook in default layout. New outline opens with my desired layout, but I'm stuck with the workbook being wrong.
2. Close Leo and reopen with --init-docks. Now I can change the workbook outline, but Leo has forgotten what layout to apply to a new outline. Rearrange panels so that both workbook and new outline have my layout. Close Leo without saving new outline. Open with --use-docks. Now workbook opens with the intended outline and new outlines also open with it, but other existing outlines all open with the wrong, default layout.
I am not going to go through this dance of closing all my current outlines, starting with --init-docks, creating a new outline, rearranging both outlines, closing Leo, and re-opening it again with --use-docks for each and every one of my existing outlines. It's unworkable. And it's fragile. For example, Leo has once again forgotten to apply this new outline to new files in --use-docks. It worked when I opened the first new outline, but when I closed that without saving so that only the workbook remained open, then created another new outline, it came up in the wrong, default layout again.
Any mistake in the sequence and you would have to start from the beginning again. It's driving me nuts. And it will drive away newcomers who will have a lot of trouble figuring it out and who have never seen any other program behave this way. Pyzo doesn't behave like this. I don't think that Pyzo has floating panels, but I'll give them up in a second if I can get some stable, understandable, reasonably intuitive behavior in exchange.
There must be a better way, but until then I'm sticking with the legacy layout.