A 529 is not a use-it-or-lose-it type of account! As far as I’m aware, all contributions you make can be taken out penalty-free. Any earnings you take out for non qualified expenses will be treated as income tax (just like a normal, taxable brokerage account) plus 10% penalty. This means that you can withdraw for whatever reasons.

The benefit of a 529 is that any growth in investment value can be used to pay for educational expenses tax free. Depending on your tax, it’s sort of like getting a 30% discount on education expenses.

You can create a brokerage account just for investing (many of the brokerage firms I listed have automatic investment options) but do be aware that you will pay taxes on all withdrawals related to earnings.