I would like to share with you my small trick
only for Prepar3D 4.4 that allows to enjoy bigger 2D RXP GNS screen positioned in front of the passenger.
Having this, you will still be able to use both - ATC and GPS windows without overlapping and continue your flight with GPS window open. Especially useful for approach the phase. As I'm not so young anymore

symbols on the 3D screen are too small and this 2D view is still useful - at least for me.
--- disclaimer - make a backup of your panel.cfg first ---
In the panel.cfg, the lines that need to be added to [Window14] section are as follows:
[Window14]
3dp_worldspace_pos_offset=0.42,0.55,0.8
3dp_pbh_offset=0,0,10
3dp_camera_transform_reference=origin
Leave all other options as is in this section.
If everyone interested is happy with that, maybe this could be added to the next official patch, as this modification will be overwritten, also if you switch between GPS options. Didn't try with Flight1, but if it also has 2D window, this should also work.