I'm using a library that turns things into ES6 Proxy objects, and another library that I think is choking because I'm passing it one of these (my code is a travesty, I know), and I couldn't figure out how to unProxy the Proxy object.
But I was just being dumb. Proxies can do anything!
I find a hack. In my case, I can't control the creation of the proxy(mobx observable values). So the solution is:
JSON.parse(JSON.stringify(your.object))