Here a a few design principals I think you should follow with the mac version layout.
1.Less used things get less attention don’t draw attention to them in your layout… Set it and forget it things like snap controls should be somewhere people usually are not looking. If you guys at McNeel buy an eye tracker It will really help. If you really need to have the full word perpendicular create a hover state that expands it.
2.Use the window version command bar Its just better in three paragraphs of ways. History, function settings,I tells me what I need to do, and again HOLDS MY ATTENTION where it matters.
3.Designers and basically everyone who works with professional software are used to interfaces that doesn’t move buttons around.(reflow is for web.) Your strength is Not and probably will not be mobile or cross platform. So design your interface around muscle memory and a desk.
4.Never, ever duplicate information in your UI. Something like a layer panel has one place and should telly you what layer you are on.
5. I want floating tool windows because they allow me to choose the things I direct my attention to.
6.Other than your interface I am sold on your program I’m going to go buy a windows box because that interface helps me work more effectively.
I studied interaction design so I could go on and on and on you will have to send me an email.