Currently only the windows platform is supported.
I want to add something to the screen scaling:
You should set AutoScaleMode to None on a Form containing a MonoGame.Forms control, otherwise the whole drawn content of the control would be misplaced due to the different viewport size.
If you still want to use DPI scaling, then you need to get the current DPI scale factor of the user and scale all control content by that factor. You can catch this factor in your Form class like this:
System.Drawing.SizeF CurrentDPIScaleFactor = AutoScaleFactor;
If you create a more complex editor environment you could split the DPI scaling of MonoGame.Forms controls and different controls, which containing text and other form controls, by using a DockPanel system and only turn the scaling off for a particular DockContent - containing a MonoGame.Forms control, and then dock it to a DockPanel.
I can reccomend this DockPanelSuit for this purpose. I'm using it in the Rogue Engine Editor and it's very nice and easy to work with, but for small editor projects it would be a bit overhelming.