Affect of meta-programming (proxy/accessors)

Proxies and accessors can return different values at different points in time or based upon self identity. This is also true for methods E.G. ``` cache = new Map() // ... x = { get usesIdentityAccessor() { return cache.get(this) } usesIdentityMethod() { return cache.get(this) } } ``` I'm trying to understand the proposal in light of these kinds of OOP based meta-programming. Not vying for any solution in particular, just a narrowing of understanding here and potential differentiation of the 2 kinds of OOP above.