A2/CO and ToH rendering reverts to 1680x1024

[OMAC]

In A2 CO and ToH, if I select 1680x1050 for 3d rendering resolution, my .cfg files usually revert to 1680x1024. Is this normal and expected? The latter resolution is not the same aspect ratio as my 1920x1200 monitor. Is the engine really rendering at the slightly wrong aspect ratio?

My TKOHPreview.cfg:

language="English";
adapter=-1;
3D_Performance=1500000;
Resolution_Bpp=32;
Resolution_W=1920;
Resolution_H=1200;
refresh=60;
winX=16;
winY=32;
winW=800;
winH=600;
winDefW=800;
winDefH=600;
Render_W=1680;
Render_H=1024;
FSAA=1;
postFX=2;
GPU_MaxFramesAhead=1000;
GPU_DetectedFramesAhead=3;
HDRPrecision=8;
lastDeviceId="";
localVRAM=915800064;
nonlocalVRAM=2147483647;
vsync=1;
AToC=7;
Windowed=0;