While I really detested the 1 pixel area that MB used to have in the past where you were allowed to grasp a panel to resize it, I think I wouldn't mind it so much if that was the case for the surrounding outside pane. Personally I don't use re-sizing the whole MB window by mouse dragging that often. So a 1px border would be o.k. by me.
Your 'hacky solution' sounds very interesting and maybe ideal for us mortal end-users, but considering how many growing pains Windows 10 seems to be experiencing, and having no certainty whatsoever about what MS might change next, it's probably not wise to invest much time and effort in such a solution at this moment. (unless you are willing to take that risk of course)
Conforming to 'a Windows 10 look' as a purpose would not be an important entry in my agenda.
I find the trend were many website and software developers are trying to use the same fonts, color schemes, icons, interfaces etc. quite unimaginative and boring to be honest.
Somebody once said: "dare to be different", and the next thing you know, everybody is trying to be different in the same way.