In the new 5.1 there is a bug that is happening for the external spawned windows. They are not keeping their position or size when Pinegrow is restarted or when you choose another workspace layout and come back to the custom saved layout.
Sometimes the code editor is also not open when it was assigned to an external window with other tabs. You have to reopen the code editor by clicking the <> icon and then reposition it. This is annoying.
Most of the time when you click the saved custom workspace it opens in a very tiny square, centered on the second monitor. Having to resize this to the complete width and height of the monitor is annoying. Also can you add the maximize icon at top of the external window so one click maximizes the window on the desired monitor?