The previous implementation used Wintun (wintun.net) which was developed originally for Wireguard but spun off into its own layer 3 tunneling driver. And yes,

The previous implementation used Wintun (wintun.net) which was developed originally for Wireguard but spun off into its own layer 3 tunneling driver. And yes, Wintun beats the pants of OpenVPN's TAP driver, but the kernel implementation is even faster yet.