I've started using Nexus couple of days ago, and noticed that the dock doesn't hide in certain applications and games running in fullscreen mode.
No matter what I did Nexus just doesn't hide itself when it should have.
So I did some research and this is what I found out.
I'm not a programmer or anything, so I could be wrong, but here goes.

First of all, there are 4 windows mode.
Normal window.
Maximized window(When you click the rectangle icon in the top right corner of a window).
Borderless maximized window(Maximized window without borders).
Fullscreen mode(This is the real fullscreen mode).

Now, in users perspective, borderless maximized window and fullscreen mode are the same, because well... they look exactly the same.
The Problem is that they are not.
Borderless maximized window is a maximized window without the borders, so thechnically it is a window.
Many applications(kmplayer, potplayer, youtube, certain games...) use this mode because it is alt-tab friendly, meaning that switching between applications is practical compared to real fullscreen mode.

Apparently, the real fullscreen mode is used mostly by games. But, some games do use borderless maximized windows mode, too.

Windows and objectdock treats borderless maximized window mode as fullscreen mode, so that the taskbar and docks doesn't show up in this mode.
Nexus on the other hand treats borderless maximized window mode as a normal window or a maximized window, thus making the docks to show up.

To make things short, I think Nexus needs to treat borderless maximized window as fullscreen mode, like windows and objectdock.

Now this is my kind of post. States the problems, researches and understands the issues involved, and even presents a solution. Well done, pax!

I'll look into this, perhaps present it as an advanced option since it is my experience that people tend to get used to the way things work, and then complain when they change even if the new makes more sense than the old.