When I was a 1K in 2018, I was on several flights where I was the only GS/1K to pre-board. I have also seen ERJ-175s where 8 or more GS’s pre-boarded. The system isn’t going to work equally well for all flights unless there is way more flexibility in it, which most of us probably wouldn’t want because frequent travelers seem to hate inconsistency nearly as much as any particular policies.

Unless GS and 1K passengers are departing United hubs on UA flights and returning on other airlines at a significant rate (which I doubt is the case) there should be the same number of GS and 1K’s on flights from out stations to hubs as there are on flights from hubs to out stations. UA doesn’t have many flights that don’t touch a hub, so nearly every UA flight is either from a hub, to a hub, or both.