That‘s what I had in mind. To run nginx on a seperate vps, so I can scale it easier. Run fediverse instances in the back, either all on one vps or on different vps. This way I could provide a hub while increase performance (due to compression and caching) and provide redundancy/load balancing if necessary.

What‘s the typical traffic you experience? Peak (Gbit/s) and average/daily traffic (GB)