Thanks, am not worried, I did get that part ;) game runs/playable on Linux but only packaged binaries for Windows as that's what I can reasonably test with my rigs. It's mostly C++ & Blueprint with no platform dependencies in the code.
it's easy enough to package for Linux in Unreal (literally a single tickbox in the packaging menu), it's opensource so feel free to package and test in Linux using the dev port of SteamVR as my vr plugin's code handles Vive compatibility as well :) or simply use the Linux version of UE4 to play test from Editor.