The key here is the fact that if the child put the money into a savings account, it was not used for support. The Kitces article also states, "(regardless of how it is spent)," That part is true. However, it must actually be spent, not put into a savings account.
"Take the case of a student who's support is $40k and the parents pay 100% of that. However, the student does have a job with $20k earned income and another $20k in unearned income (or taxable scholarship) that they put into a savings account and don't spend on support."
@clobber88
