Streaming Videos from Unlimited Object Storages

I'm working on a project where we aim to provide some sort of video (not actual viddeo format, its our own custom format that gets decrypted on the client side) streaming service (just playbacks and nothing live) that allows users to watch videos stored in their own cloud storage accounts. Our users can submit their storage accounts to our platform, and since many of these accounts come with unlimited storage, we have access to a vast amount of video content spread across various cloud providers. So mounting all these provides is not a good option for us. I was thinking of using Copy and adding Range-Bytes header, but not sure if that will do the trick or not.

What’s the best way to handle this setup?
Is Rclone the right tool to do this?