It is very difficult to misconfigure Wireguard -- there's just not that much to tune aside from MTU. We've had a 1 Gbps tunnel between AWS and OVH for years and it worked mostly fine, except for the handful of times OVH's DDOS mitigation kicked in and killed the tunnel. The issue is when you start wanting to go beyond 1 Gbps.

I think AWS will do 5 Gbps with a capable peer -- which is their limit for a single flow [1] -- but you might need to tell them first so they don't kill public networking on the instance though. I found that UDP iperf tests reliably got my instance's internet shut off, so keep that in mind. On the other hand, OVH will happily do 5-ish Gbps to/from my EC2 instance in a TCP iperf test, but won't tolerate more than 1 Gbps of inbound UDP. OVH support has indicated that this is expected, though they do not document that limitation and it seemed that both their support and network engineering people were themselves unaware of that limit until we complained. They don't seem to have the same limits on ESP, which is why I developed an interest in ipsec arcana.

[1] https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-inst...