Vorpx and Revive are two totally different concpets for two totally different use cases.
– Revive is an API wrapper that translates Oculus runtime functions into openVR calls, this enables you to play many Rift games on the Vive.
– Vorpx is a stereo injector with headtracking support for mouse/analog emulation (and many more neat features), which enables you to play many non-VR games in both of the current HMDs.
Subnautica is a Rift game and is listed on the Revive compatibility list as working, so that is where you need to focus your attention.
Vorpx and Revive can be installed alongside each other without problems, but they can’t both hook into a game at the same time (which would be pointless anyway since Vorpx is for non-VR games and Revive is for rift games).