1050 ST / 1050 GT digital display question

I have a 2011 1050GT and the trip meter does not want to reset, not the end of the world but it lead me to notice something else. If I pressed all 3 buttons that control the digital display for around 6 seconds the display changed to 1. If I pressed the right hand button 2 and then 3 and back to 1. The middle button saved the setting. My 2008 1050ST has exactly the same feature.

I changed the setting from 1 to 2 and rode the 45 miles to work and noticed that the average MPG was down by around 6 mpg but the bike did not feel any different to ride. I changed back to mode 1 and the MPG recovered. Do these numbers represent different engine mappings and if so what are they.

As a side issue on a 1050ST the 'miles remaining with current fuel' function always works. On the GT when you get below 2 bars on the fuel gauge the 'miles remaining' display stops working. Its not a problem I just wondered why Triumph felt the need to make the change in functionality. Anyone know why this change was introduced?

Just curious to understand more about the bikes. And this did not resolve the problem with not being able to reset the trip meter.