Well, my policy is "don't use sharp knives because they can hurt you, but if you really need one you can go and get one yourself". There are already lots of excellent JS libraries out there and I don't see why we should reinvent the wheel - you can just go and integrate one yourself, if you're aware of the possible shortcomings of the library for games.
If your code really is that simple, it should be fine since it appears to avoid allocations. But then if that's all the code is, I'd just use x/y values myself to avoid dependency on a whole library.
You can use the dependency field, but it can work better just pasting an entire JS library to the top of the runtime.js file. The Physics behavior has the whole Box2D library pasted in to the top.