Order in which index entries should be reused is unspecified.

The description of the index property on Gamepad states:
"if a gamepad is disconnected, and subsequently the same or a different gamepad is then connected, index entries must be reused."

So if I have 2 gamepads, then disconnect index 0, then connect a new gamepad, it should reuse index 0.

If I have 3 gamepads, then disconnect index 1, then connect a new gamepad, it should reuse index 1.

But what if I have 3 gamepads, disconnect index 1, then disconnect index 0.
Then connect a new gamepad.

Which index should it reuse?  0, which is the lowest unused index?  Or 1, because it was the first disconnected index?

I would say 0, and suggest the spec state something like:
"if a gamepad is disconnected, and subsequently the same or a different gamepad is then connected, the lowest previously used index must be reused."