sorry refunds on amended returns can't be used directly to but I Binds

Amended return. Don’t attach Form 8888
to Form 1040-X. A refund on an amended
return can’t be directly deposited to an
account or used to buy savings bonds.

Why can't you buy the bonds yourself when you get the refund?   What filing deadline is Sept 15?   You can efile a 2020 return and amended return until Oct 15.   After that you can print and mail returns.   You have 3 years to file for a refund.

When you amend a tax return your refund is sent as a paper check by the IRS.   There are no other options for how to get your refund for an amended return.

Thanks. There are limits on how many I bonds I can purchase annually. One avenue is via my tax return. I also max out by purchasing with cash as well.  But the tax return avenue lets me buy more I bonds than I'd otherwise be allowed. I'd hoped by amending my return I could take advantage of the likely increase in I bond interest rates set for November. Yes, my filing deadline on an extension isn't until October. Same issue.  

Thanks. Very helpful.