529 Plan - Can I have one in my child's name and one in my name, but later change the beneficiary of my 529 to the same child?

Trying to figure out how to maximize 529 savings. I have a 529 setup for my 3 year old ("Child 529"). No other children. I didn't realize I could setup a 529 for myself ("Parent 529") and that I could then later change the beneficiary of the Parent 529 to my child. Would I be able to, essentially, double-dip by maxing out contributions to both the Child 529 and the Parent 529 and ultimately have my child as beneficiary of both? Example: Child 529 has enough $$ to pay for 4 years of college. Child uses all the money in the Child 529 when he goes to college. After child graduates from college, I change the beneficiary of the Parent 529 to my child which he could then use for grad school, convert (in part) to a Roth IRA, let the investment roll to pay for his own kids college, etc.?