Redo the dang loot system.

If someone's inventory is full, as soon as loot is available, toss a warning up for them so they can throw something out. Ideally, have a 'holding space' for like... 3-4 items, where if your inventory is full it goes into that space until you have discarded something, at which point, the next item in the 'holding space' falls into your inventory. (I've had friends whose inventory was full after a map night lose out on things they wanted. And I know someone who missed out on an ultimate clear totem because their inventory was full and they'd forgotten.)

If you cannot roll on something ("You have already obtained one <X> for the week.") then just automatically pass on it. If it's something with a Unique flag and I already have it in my inventory, pass there, too! You cannot open a coffer when bound by duty, you cannot access your chocobo saddlebag and retainers, there's literally no way to resolve that short of doing "Pass" anyway. (Or throwing out the unique thing and then... rolling the identical thing, solely to deny it to someone else. Which is just sort of a jerk move and doesn't really need to be supported.)

And for the love of the Twelve, give me a 'Greed All' and 'Pass All' button! And ideally a "remember for the rest of this instance" checkbox; I really, really, really never mean to roll on anything in Sastasha. I promise you this. Let me just tell the game that and never see a loot dialogue in there again.