I understand there may be times when you must leave your seat during Mass to use the bathroom (especially if the need comes during Mass without much warning & you cannot wait), change a baby’s diaper in the ladies’ room, or calm down a child as examples.
In your opinion, when those needs listed above or related are handled, when do you return to your seat? Does it matter where you were seated prior to your need to get up? (as I think if you sit closer to the front compared to the back or middle of the church.)
To me, I was raised to not come back until there was a time the people were standing especially if you had to get up while people were still seated if possible. Also, to not leave during the Consecration unless it was very urgent to do so to handle such things listed in my first paragraph.