Yes, it can be reset but the question is how to add mileage. If you upgrade to the 1030 from another device, there is no simple way to add the mileage from the old device to the 1030.
I have fixed Edit Edge Data to handle rollover, available soon on the App Store.
Yes it can be reset as I just did if for all 4 of my profiles (road / mountain / gravel / indoor). Not sure when this function was added or if it was here all along, as I only upgraded from my Edge 1000 to the Edge 1030 back in April of 2019. So this is my first odometer reset with the 1030.
Any who click on History > Totals > select the profile to reset i.e. Road > Delete > Confirm and you're done. Repeat for all profiles if you are wanting to reset all to zero for the new year.