I want the opposite to be true, so please indulge me.
assume non-custodial parent owned, student beneficiary.
This site seems to be agreeing with student support:
https://dsjcpa.com/student-dependent-support-issues/
Section 529 Distributions (QTP Plans)
In general, any distribution is includible in the gross income of the student unless it is used for qualified education expenses (tuition, fees, books, supplies, and equipment required for enrollment, plus the cost of room and board). If the distribution exceeds qualified education expenses, a portion is taxed to the student and will usually be subject to a 10% penalty tax.
Since the student is taxed on the QTP distributions (or excluded from the student’s gross income), they are generally considered as contributed by the student for his or her support.
This thread it seems the user got an email from the IRS indicating student support:
https://forum.savingforcollege.com/t/distributions-from-529-plans-and-parent-support/10834
Another argument I think in my favor that that 529 distributions from non-custodial parent are considered student unearned income on the tax return and student untaxed income on the fafsa EFC calculations.