Additional upgrades in Snake Eye past the first grant the ability a chance for the next Double-Up used to immediately roll whatever is required (between 1 and 6) to reach a total of 11 in the roll, instead of an automatic 1. This check is only made if the current roll is at 5 or higher. If the check fails or is not made, Double-Up will result in a roll of 1 as normal. The chance for this happening increases by 5% for each point in Snake Eye NOT including the first, up to a maximum of 20% (the in-game text stating 10% per upgrade is an error)
The augmented Commodore Culottes +2 grant the ability a 4% chance to negate its recast time, allowing it to immediately be used again. The chance of this occuring is 4% for each point in Snake Eye including the first, up to a maximum of 20%.