I hope that somebody can help me to build a data field/widget that will turn the back light on if an auto lap / new lap comes on after sunset , during an activity (very much similar to the 'till sunset' back light mode on fenix 1)
A data field is active inside the built-in activity applications, but doesn't have access to the backlight. A widget can turn the backlight on/off, but doesn't have access to information about your current activity. In other words, I'm pretty sure this isn't possible from ConnectIQ.