[martheen]

It depends on the OpenVZ kernel, some later version can use WG. But OpenVZ is dying anyway so if someone use a still supported container technology, WG is probably available.

Depending on the ISP setup, sometimes WG can be less reliable due to MTU and/or UDP filtering, I remember an ISP from years ago where WG don't work only on certain hours, while OpenVPN running on the same server still work.

[Jnr]

Wireguard can run in userspace mode if the kernel module is not available.

Changing the MTU for Wireguard to 1280 usually helps a lot with reliability and throughput.