presigned URL threshold based on regex or other patterns

[robes]

We have a use case where hatrac data is serving up gene annotation tracks consumed by the UCSC genome browser (GB). The GB does not follow redirects and so this breaks their client if we threshold simply on file size. What we need is some other mechanism, probably a regex, prefix, or other pattern based method to decide if a fetch request should be redirected to a presigned URL.

This has a high priority for FaceBase because we have track files the size of nearly 2GB so using the size threshold is not very effective for us.