Super interesting project. But I cannot understand why you support only EC2 instances as clients. For what it is worth, it looks strange and limiting. By default I expect to be able to use Regatta Storage from everywhere: from my local machine, from my Docker containers running elsewhere, etc.
This isn't a technical limitation, per se, but a time limitation in terms of getting to the place where we feel comfortable supporting those environments for the public. I still wouldn't recommend mounting it from a local environment (because NFS behaves pretty poorly when it can't connect to the server), but we do have a CSI driver for containers running in K8s. We expect that customers will get the best experience if their instances are very close (latency-wise) to our instances, which is why we only support access from us-east-1 in AWS. We expect to launch in more regions and clouds in the coming months.
If you want early access to other clouds or the CSI driver, feel free to email hleath [at] regattastorage.com.