Don't know if this may be of interest, but I use the pop-ups at the side, in line with the new message bar position for aircraft that don't have visible RADAR and RWR without scrolling the cockpit.
The only problem with the RWR is that it's always on. But you don't have to add it. In fact some aircraft don't need it because the RWR is visible in the cockpit. If the aircraft already has visible RWR, I just cancel [Display006]
If it has visible radar, I just make the width and height entries in [Display004] set at zero. (An ancient trick)
I keep a set of different HUDDATA.inis for different aircraft, and then just slot the appropriate one into the flight folder.
These are the changed and added entries in the HUDDATA.ini from the FLIGHT folder for this A-6, a slightly modified Razbam.
[Display004]
DisplayType=RADAR
PosX=0.048
PosY=0.615
Width=0.1625
Height=0.217
Alpha=1.0
InitTime=2.0
[Display006]
DisplayType=RWR
PosX=0.147
PosY=0.490
Width=0.06375
Height=0.1125
Alpha=1.0
InitTime=2.0