Hi guys, thanks for your feedback so far.
Fortunately we finalized some work on replay stuff that was mostly done already, so we'll compress replays with zstandard instead of (zip encoded with base64). Support will come in the next client release and we'll need to find a way to convert all the old replays. This will be a big breaking change for some tools out there, but it's the best chance we have.
Some words on the alternative suggested here:
While renting storage in the cloud with some cheap providers is possible of course it massively increases develop and (more important) maintenance efforts which I'm not willing to pull. Storage in our Hetzner datacenter would be possible though as it can be natively integrated into the existing server infrastructure. Nevertheless we still strive for a cost neutral solution if possible.
Eventually this topic will reappear in a few years again, so the discussion is not off the table forever.
We'll see which storage savings we can achieve with the current solution.