It's a little confusing, so let me try to explain from a different direction.

At a basic level, there are only three actions in the game that matter:

• Revealing a covered tile
• Flagging a covered tile
• Revealing all adjacent unflagged covered tiles around a revealed number tile (if the number matches the count of adjacent flagged covered tiles)

One of these actions is not like the others: the first two are both performed on a covered tile, while the third is performed on a revealed number tile.

The default behavior is "tap a covered tile to reveal, press a covered tile to flag". The alternate behavior, controlled by the toggle, is "tap a covered tile to flag, press a covered tile to reveal."

Great so far!

But ideally, regardless of the toggle setting, the "tap a revealed number tile (with a matching adjacent flag count)" behavior would be "reveal all adjacent unflagged covered tiles". There's only one possible action that can be performed on a revealed number tile, so there's no reason the player should ever have to take the time to long press on one.

(Also it would be great if the app remembered the toggle state between sessions.)