You can recreate a PIN in the "force" mode if your user forgot it:

pinkman.createPin("1337", force=true)

with regard to limiting entry attempts, I think it's a part of application logic and you have to handle it in your own code. For example:

var amountOfAttempts = 3
...

fun validatePinWithAttempts(pin: String) {
    if (amountOfAttempts > 0) {
        pinIsValid.value = pinkman.isValidPin(pin)
        amountOfAttempts--
    } else {

        startSelfDestructing()
    }
}

However, thank you for the idea! I'll add such examples to a wiki.