Remember, you control the 529 until the designee turns 18yr. Up until then you can very easily change the designee as you see fit.
After they turn 18 they control the account you are locked out so have the kid add you so you have visibility on the account.
They are not attuned to managing a ‘portfolio’ so you can help them while they focus on studies.
We had the situation where all of the 529 was not spent and grandpa wanted the rest to be used for a down payment. (no one else to transfer to) Say hello to 10% penalty and tax.