Also, by the way, you CAN have hotkeys, or remote commands, for controlling the zoom function.
You should research Media Center Core Commands (MCC) and pay attention to 22025 and 22026.
I have researched them, and they are non functional for my purpose and environment. As far as I can determine, 22025 doesn't take effect at initial launch unlike, for example VLC
"D:\Apps\VLC 3.10\vlc\vlc.exe" --monitor-par 23:16 --zoom 1.35 --fullscreen
and since MC occupies the entire screen when playing video, it's hard to run a command line window without a second monitor, which isn't going to fly in an Home Theater environment.
MPC:
[HKEY_CURRENT_USER\Software\MPC-HC\MPC-HC\Settings\PnSPresets]
"Preset0"="1.77,0.500,0.500,0.700,1.000"
"Preset1"="1.85,0.500,0.500,0.720,1.037"
"Preset2"="2.00,0.500,0.500,0.780,1.126"
"Preset3"="2.20,0.500,0.500,0.860,1.243"
"Preset4"="2.40,0.500,0.500,0.925,1.349"
"Preset5"="2.55,0.500,0.500,0.970,1.430"
"Preset6"="2.76,0.500,0.500,1.070,1.550"
Zoom Player
[HKEY_CURRENT_USER\Software\VirtuaMedia\ZoomPlayer]
"Preset2"="2: XOfs[268] YOfs[-20] Width[1384] Height[1120]"
"PresetCustomAR2"="2: Width[1.77] Height[1]"
"Preset3"="3: XOfs[228] YOfs[-70] Width[1460] Height[1230]"
"PresetCustomAR3"="3: Width[1.85] Height[1]"
"Preset4"="4: XOfs[140] YOfs[-130] Width[1640] Height[1340]"
"Preset5"="5: XOfs[60] YOfs[-188] Width[1800] Height[1460]"
"PresetCustomAR5"="5: Width[2.20] Height[1]"
"Preset6"="6: XOfs[30] YOfs[-237] Width[1860] Height[1550]"
"PresetCustomAR6"="6: Width[2.40] Height[1]"
"Preset7"="7: XOfs[-27] YOfs[-300] Width[1980] Height[1680]"
"PresetCustomAR7"="7: Width[2.55] Height[1]"
"Preset8"="8: XOfs[-72] YOfs[-330] Width[2060] Height[1720]"
"PresetCustomAR8"="8: Width[2.76] Height[1]"
"Preset9"="9: XOfs[-92] YOfs[-340] Width[2100] Height[1740]"
"PresetCustomAR9"="9: Width[2.85] Height[1]"