Minesweeper upgrade with 120 ammo could be a thing.
Minesweeper upgrade would probably be too ineffective to be a good idea. When the flail was activated, the Sherman gun had to point to the rear (couldn't fire), and the tank's speed was very limited. Obviously, the mines would also damage the flail, which would have to be replaced, although I wouldn't mind overlooking this fact, but even if we ignored this, the minesweeper upgrade would be too hard to use and too limited to be worth it.