This is a fascinating and highly specific hardware hacking combination. The post you’re referring to likely discusses using an (often an Uno or Leonardo with ATmega16U2) in conjunction with Checkm8 —the permanent bootrom exploit for certain Apple devices (iPhone 4S through iPhone X)—to achieve something “exclusive,” probably bypassing some software restriction.
A5 was taken aback by the offer, but they knew that working with Exclusive could be a game-changer. They agreed to collaborate, and together they set to work on a custom Arduino device that could exploit the Checkm8 vulnerability. arduino+a5+checkm8+exclusive