We only provide Unity and Unreal Engine SDKs at this time, but are exploring Native and possibly other options in the future.

We don't offer a native SDK at the moment, but some other developers have successfully used the OpenXR loader and header files from our Unreal Engine SDK to create their own native applications. 

A native framework that I used on VRX before is StereoKit which is open source. GitHub - StereoKit/StereoKit: An easy-to-use XR engine for building AR and VR applications with C# and OpenXR! Perhaps you can use this as a reference point.  Here some setup detail  Snapdragon Spaces OpenXR Custom Loader Setup · StereoKit/StereoKit · Discussion #790 · GitHub. 

Please note that while these solutions work, they are not officially supported and I can not guarantee you won't run into issues at some point. 

We are evaluating developer and industry needs which may lead to a decision on offering a native SDK in the future. At the moment there's nothing concrete on the roadmap that I can to share.