True that there is a 3 hour EUA but you are not correct in saying "everything will dump into F." CO does not release all the A inventory to F at the 3 hour window. They keep some for walkups - and my experience is they keep most of it.

Now, if there are no walkups that inventory will go to elites onboard - on the battlefield - but, by this time a late-ckecking-in-platinum ("Platinum X") can get on the SB UG list behind Joe Blow, if Joe Blow is a platinum companion who has checked in with another platinum earlier in time than Platinum X.

That's great for me because I often bring non elite companions or silvers, golds...but I have jad these people be input as platinums onto the SB UG list and seen them get the UG ahead of other platinums quite regularly - a good example of this is when we fly eastbound redeyes connection to early morning flights on the east coast - because we will almost always have checked in earlier than everyone else.

I used to think the CO system prioritized platinums and then platinum companions, to avoid this situation, but within the last few months after getting literally 10 or so non elites upgraded ahead of other platinums on the list, I have seen that either this is not true or agents simply just use the regular-platinum code to put companions on the list.

This is why I asked the question a few months ago, re: does the computer system troll the UG list to correlate people's actual elite status with the list. The answer is no - if Joe Blow is put on the list as a platinum, he stays on the list as a platinum even if he is a non elite, a gold, etc. I've now confirmed this because I have in my possession a FC manifest printout showing a nonelite companion of mine as "platinum."