The downside is this service is not up-to-the-minute accurate. I rented a new-construction house and it was the better part of a year before it made it into the USPS address correction database, despite receiving mail just fine.
Might be acceptable collateral damage, but it’d exclude some people.
I think offering suggested edit is ok but requiring the edit be accepted is unwise.
You would have to tell the user “use the corrected/matched one only” though. Some sites offer the correction but don’t make you use it.