Sampled Pixels from Render Target Being Clamped in Package Build

Hello, using Unreal Engine to make a VR project and in the VR Preview everything is working as expected, but my RTF RGBA16f render target which I am using to encode local position data in the pixels (which can be negative or greater than 1.0) are being clamped when sampled on the package build to 0-1; but not in the VR Preview or PIE modes. It seems like there's some subtle difference between Directx12 and Vulkan regarding the texture formats? What can be done to resolve the issue? It's pretty important and would be a massive inconvenience to refactor things to be normalized in a 0-1 range. 

It is preferable to be able to preserve and sample the raw values as originally encoded.