Cross-Platform Advice / Guidance

Hi,

I'm currently building VR projects in Unity3D and I realize that an Android build is needed for the Quest, while a PC build supports the Rift and other tethered devices; is there a best place to start if I'd like to build projects that eventually support the Quest, Rift, and Steam platforms? I'm aware of SteamVR, OpenVR, and Oculus Integration asset, I'd like to stay organized with my approach, and any advice is appreciated? Additionally, for headsets like PSVR and Samsung Odyssey, is there a preferred approach that optimizes cross-platformability and adopts a "work smarter, not harder" methodology so that precious development hours aren't unnecessarily misallocated for optimal productivity?

Thanks and take care