Yep, that is the right way! CF also has some startup programs but I think it can be easier to get going in AWS! 🐶🐾🫡
Discussion
It's also easy to add a non-AWS-CloudFront domain for CDN to the S3 bucket. So, with a CNAME record at Cloudflare could be used (ex: files.nostr.build) and with the $20/m Pro plan to enable the Lossy image optimisation from the edge, rather than server-side. That would also deliver WebP to help speed up delivery for web-based nostr clients.