A lesser issue, and perhaps more ameneable to research, is whether allele changes have predictable consequenses. There are, of course at least levels of consequense. The first would be structural. Can the resulting organism survive. The second consequence would be ecological. How does the change affect the organism's reproductive success in a world teeming with competitors and preditors. Can this be predicted, even in principle?
But if the designer is a cosmic ancestor with vision/mind of an extra temporal dimension - and especially considering God the Creator outside of space/time - then the objection of unpredictability fails because the future is known for every design or design change.
If evidenced, your objection would preclude corporeal entities with four dimensional vision/minds moving on worldlines within the hypercube of space/time from being the "designer" in intelligent design theory.
That's a useful definition which I assert would narrow the field for possible designers to either outside the hypercube (God) or as cosmic ancestry (aliens, collective consciousness) with extra temporal dimension vision/mind.
I agree with js1138 that there's not much point in doing any designing unless the outcome is reasonably predictable.
The remarks of js1138, and Alamo-Girl's observation that the ability to predict the consequences of design pretty much rules out any natural designer (as I understand her remarks), would seem to demolish any pretentions of the ID movement that they are advocating anything but a religious doctrine.