Assuming there wont be any egress fess forever on Cloudflare R2 is a bit risky IMHO if you read stuff like [0]. Especially if you build a product on top of it.
The first step is to get to a scale where you piss off the Cloudflare sales team. FILE0 is far from that. Whenever that will be the case we can think about solutions, but this wouldn't be a good enough reason not to use them, and the free egress until we can.