EMR Serverless Outbound Internet Access without NAT Gateway

In terms of requesting features, please reach out to your local AWS team to discuss.

If you only need access a few times a day is there scope to do something completely different? For example, if access does not need to be synchronous could you have the workload request the data that it requires via (say) a SQS message; have a Lambda function triggered from that which retrieves (or sends) the appropriate data; then put the result into S3 or back into another SQS message?

Yes, it's more work for you but it might be less expensive in terms of AWS services. That said, your time and effort is actually worth something so perhaps running NAT Gateway when you need it is actually cost effective.