If it can make a wall, can't it climb it's own wall? If God can make it I am pretty sure the creator can climb it.
Depends if Example makes it so that they can climb it. If they're able to do "everything", then they cannot design it to be unclimbable to themself, wheras a simple engineer could make a really tall wall which they can't really climb themselves.
Which in a way, being able to do anything means you're not unable to make it so you can't do something, a simple task ones who aren't omnipotent have easily figured out.