One thing to consider is that EFS is priced at 10x the cost of the most expensive tier of S3 storage ($0.30/Gbyte vs $0.03/Gbyte). If they are just static asse

One thing to consider is that EFS is priced at 10x the cost of the most expensive tier of S3 storage ($0.30/Gbyte vs $0.03/Gbyte). If they are just static assets, you would do better to put them in an S3 bucket, set appropriate Cache-Control headers and serve them via Cloudfront. This reduces your outbound bandwidth cost to the Internet versus EC2/S3, and yields better performance.