OpenXR alternative for 2019 project?

Hey VR devs,

I’ve got a project that relies on some assets that simply will not work beyond Unity 2019. What is the recommended solution for 2019 and previous versions to ship a VR product that is compatible with all device types? My project is currently using the Oculus plug-in, and I’d love to find something that won’t require too much re-work.

Thanks in advance.

SteamVR for PC and Oculus for meta quest native builds if you got them.
SteamVR supports most headsets