Unfortunately, there might be too much IP in the code (it was for a team presentation at a company I contract for). I could probably scrub that out and put it up on GitHub, though.
We've been using volta at sentry.io for probably close to two years now, and I have to say, it's one of those tools I almost never think about because it legitimately "just works" (and is very very fast).
It has definitely helped to keep our team's environment in sync as we grow in # of people building Sentry. It's pretty much eliminated the need to ask 'are you on node / yarn x.y.z?