congratulations on releasing the latest revision, it's an incredible leap from the previous (public) one, in terms of usability and stability.
There is one thing where the new version performs worse than previous revisions, though - the window behavior. Considering that the title bar is now styled and contains elements I guess you are using a custom implementation instead of a default window object which allows for more flexibility but lacks some of the default functionality.
If that's the case, you are probably already well aware and I'm not telling you any news. Just to highlight what I mean, I have compiled a list of things I noticed. Most of them are pretty small things but are incredibly noticable because you expect a window the behave a certain way, i.e. like all other windows on your OS. If it doesn't it sticks out like a sore thumb.
Prerequisites: Window state is maximised
Action: Dragging the title bar with the mouse cursor to a new location
Expected behavior: Window is moved to the new location and the window state changes to normal
Actual behavior: Window is moved to the new location but the window state remains maximised. This has follow up issues e.g. incorrect styling of the window edges, the window isn't resized back to normal and also can't be resized manually since that isn't allowed in a maximized state.
Prerequisites: Window state is normal
Action: Moving the mouse to the upper border of the window and dragging up- or downwards
Expected behavior: The cursor changes to a resize arrow and the window is resized vertically
Actual behavior: Resizing is only possible from the bottom border, sides and four edges of the window, but not from the top border.
Prerequisites: Window state is normal
Action: Dragging the window to the edge of the screen
Expected behavior: The window should snap to the respective area of the screen.
Actual behavior: Nothing happens. Snapping with [Windows key] + [arrow key] is respected, though.
Prerequisites: More than one tab opened
Action: Clicking a tab with the middle mouse button
Expected behavior: The tab should close itself.
Actual behavior: Nothing happens. Not sure if this is actually best practise, but it works in Firefox, Chrome and Edge, so I kind of got used to it.
Prerequisites: Window is in normal state
Action: Dragging a corner or border of the window
Expected behavior: The mouse cursor should turn to a resize cursor and the window should resize.
Actual behavior: This actually works, but for some reason I found it extremely hard to position the mouse cursor correctly, compared to other windows. I'm not sure if the trigger area is actually smaller than the one of other windows or if it's just subjectively harder to due to the somewhat big border. See the screenshot with a comparison between MM, Firefox and the file explorer below to see what I mean.
