I got 220+ Mbps as client through the RT-AC86U.
Running same connection through my PC with same encryption: 500 Mbps.
If you want higher speed than 220+ I advice you to go for VPN through Wireguard!
thanks that is interesting to know, did you by chance notice erratic speeds on your 220+ Mbps with AC86u also ?
I hear the reliability of openvpn performance around 250-300Mbps is poor with speeds dipping often then up again, Wiregaurd no such issue. Maybe openvpn is finally showing its age.