I'm trying to be more intentional about monitoring load on the HPB during calls. I'll update this posts occasionally with some numbers.
Current setup: Hetzner CPX31 VPS.
4 concurrent users (3 with video):
Max CPU Usage: 8.5%
Max Memory Usage: +-0% from idle
Peak Bandwidth: 0.86MB/s sent, 0.57MB/s recieved