Alright, I thought there was an issue with my testing, but it appears that they are pushed at (or near to) the end of the frame. It would push β1β in this case.
In traditional replication, Dirty actors and properties are βpolledβ at the end of the game frame for changes. Remember that you are not garaunteed to receive all UPROPERTY changes, you are ONLY garaunteed to eventually catch up to the latest state.
Changing properties in quick succession will almost certainly result in some of those interim changes being dropped in the real world.