Whether the selected row should say the new order or filter before its own name, until the reader moves. Set when the order or filter changed from the keyboard: the summary and the first object then arrive as one utterance on the focus move, instead of a live region and a focus move talking over each other.
Whether focus should stay where it is rather than follow the selection: set only when a button changed the order or filter, so pressing it again presses it again. Any key that moves the list or the selection clears it, from wherever focus was -- a key that changed the list while focus stayed on a button would change it out of earshot.
Counts the arrangements the list has been shown in -- each opening, each new order, each new filter. The dialog keys its rows by it, so a new arrangement mounts new rows and moving focus onto the first is a focus change the screen reader announces, even when the selection was already on row 0.