I think the reason there are only time rankings is because the google minesweeper doesn't show any other stats. Adding 3bv/s means we have to manually count (to check if we get a pb and then again for the verification).

Also there is no explanation in google minesweeper of what 3bv is, so new players won't understand the category. I feel like it's good to keep it simple here and leave 3bv/s and eff for the official versions of the game.

I think we could have it as a category as it fundamentally changes how you play speed, and although it would compete with flagging in the normal leaderbord anyways if your personal best is no flags, having its own leaderboard would be cool to see other people's times as well.

I think if anything, a category where you need to beat a certain number of boards in the minimum time possible (like endurance in wom) could be interesting. I would prefer if something like nf was added first though, but all ideas are welcome