Well, for one you could get some extra hands implementing simple features (and bug fixes) in your backlog, at first.
If someone needs a specific feature and has some coding knowledge then he/she can contribute some of his/her time to the cause, making the project advance faster. You are the final arbiter for what goes in, of course.
And considering the case where you don’t want to spend time “nurturing” an open source community (say you find it’s too much overhead), a simple “code dump”-style open-sourcing would be nice; just indicate that you don’t accept contributions for now. To developers like me this is a nice reassurance that the project will keep going on whatever happens, and won’t be shut down due to unforeseen events (even if that seems unlikely).
By the way, I got to try Skybox on Oculus Go the other day (I only tried the iOS version before) and I must say it’s some top-notch, polished software! Good job! :)