Originally Posted by
Often1
I don't board without checking with the GA. If I am in the ballpark for an UG, I ask whether I should board or wait. Inevitably the GA says he will come find me if there is space. In this case, it doesn't appear that OP asked the GA and it was just one of those flights were the GA didn't go fishing people upstream.
I do the same, partly to let the GA know that I will be easy to find but also to make them aware that I’m paying attention to what they are doing...