According to what has been previously published here by those who attended the DO last year, and in my own personal experience, if you board the aircraft you *technically* lose your upgrade chance... meaning on the 2nd example you should have been upgraded.

However, there are GA's that will actually board the aircraft and pull up the person who was originally #1 on the list which is what happened to you.

Personally, and I've said it before, I don't have a preference either way as to what the process is but I would like to see if enforced consistently at all stations so that you know whether or not you should board or hang out at the gate.