OK that makes sense. So because you got the factory common_dll the first thing you want to do is make a backup copy of it, then use a Hex editor and change the bytes at offsets 0x53C7 and 0x0AEEDF from E1 to E3. Copy the modified common_dll to the camera.
Then restart the camera and make sure it still starts normally. Then you can edit your decrypted conf, make IRwidth int32 320, IRheight int32 240, targetNoiseMk int32 0.
Encrypt it using the cfccgf_v2.py. Copy to the camera. Turn the camera off, remove the battery for a few sec, put back in and restart. This should do the Res mod.