Agreed. Take full advantage of the AOTC--one of the best kept secrets--starting in tax year 2019, if you wish. Understand that, if a child graduates in the typical 4 academic years, that will span 5 tax years--so there will be one tax year in which you can not use the AOTC for said child.
And when you do dip into the child's 529, be sure to set aside $4000 of eligible expenses NOT reimbursed by the 529 in a given tax year in order to maximize the effect of the AOTC for that tax year (in other words, no double-dipping--you can't claim the AOTC for expenses paid by a 529).