Hi Whipon,
Sorry I missed your thread.
If you want to reduce the left border you need to reduce the value here:
crt_range0 15625-15750, 49.50-65.00, 2.000, 4.700, 8.000, 0.064, 0.192, 1.024, 0, 0, 192, 256, 448, 512
Start with a value around 6.000 and increase or decrease it as required.
After that you may need to compensate the right border too, this one is controlled by this value:
crt_range0 15625-15750, 49.50-65.00, 2.000, 4.700, 8.000, 0.064, 0.192, 1.024, 0, 0, 192, 256, 448, 512
By adjusting your potentiometers to cover the 54 - 61 Hz range (so MK is in sync), you're already in the sweat spot. The problem with bios screens is they use 70 Hz so it's hard or impossible to get those in sync and still don't affect the games. A crt_range won't help here.