would it be outrageously mean to connect a 100ft (minimum) leash to a parrot's ankle *before* opening the cage?
Leaving aside the difficulty in doing that with no cage access, that would strike me as dangerous to the bird. Birds are unfortunately easy to strangle, which is why cage bar spacing is so very important. Also, 100' of leash is going to be extremely heavy, as far as the parrot - even a large parrot - is concerned.