Without doing a search on the display I cannot talk to its particulars, only generalities at this point. You will need to identify the display model and download the shop manual to play with it.
Metric Conversion Hack: 1 Mi. = 1.61 Km. So Kilometers are about 40% smaller than Miles. Set your display to read in Km and the 26-inch wheel size to 40% smaller, 16 inches. The display number for speed will still read in Mph but will say that it is Kph. "30Kph" will be actually 30Mph. The speed limit will now be increased by 40% in the programing. This does not account for physics. A big guy on a heavy bike will still be a big guy on a heavy bike.
Please report back on how this simple hack changes the dynamics at starts and the top-end performance on your bike. On some bikes it makes a significant change. It does not change your local laws, or the warrantee, so be careful. I have sometimes told displays on 29er bikes that they have 10in wheels. Is it unethical to lie to my display? I hope this helps. Good luck.