I know more now than I did whenever those things started. You can lose more (via consequences) by having a 529 than the tax benefits of utilizing it as so much is available already as a tithe paying member without the investment restrictions. If your kid is going to go to Harvard or something expensive, it might change the formula - I haven't done the math, but not BYU or any of her less expensive stepsisters (I have personally lived the math).

I would save outside of a 529. Use it to build a "tithing fund" equivalent. Do DIK's to rotate and harvest the tax liability over time. Use the same for mission funds. If you need school funds in the year your kid goes to school, contribute to the 529 if it is advantageous and take the tax write off just before you need the funds to avoid problems. You may choose not to do it at that time...

529s create all kinds of unintended consequences. I need to get back to work, but saw this and wanted to stop everyone from making the same mistake I did of doing a 529 long in advance of need.

I would never recommend that someone does a 529 much in advance, if at all.