I did a test by re-defining the X,Y,W,H of all three of my RDP windows. Here's how the triggers are set...
A: X=974, Y=-983, W=1700, H=990
C: X=1078, Y=-1023, W=1700, H=990
D: X=1194, Y=-1080, W=1700, H=990
Here's how the windows are positions after the trigger runs...
A: X=967, Y=-983, W=1714, H=997
C: X=1071, Y=-1023, W=1714, H=997
D: X=1187, Y=-1080, W=1714, H=997
Here's the difference between defined and actual...
A: X=-7, Y=0, W=+14, H=+7
C: X=-7, Y=0, W=+14, H=+7
D: X=-7, Y=0, W=+14, H=+7
So, to your point, I think I need to add 7 to X, subtract 14 from W, and subtract 7 from H. Does this jibe with the discrepancies you see in code?