I did try seaweedfs ~half a year ago and I had issues with setting up users through terraform module (if I recall correctly, users endpoint were not correctly responding on delete), and lack of S3 expiry rules (you needed to use seaweedfs configuration or API for that). Other than that, I was pretty happy with it.
Thanks! I am sure most of the bugs are fixed now. SeaweedFS now should have the most complete S3 API support now.
(I work on SeaweedFS)