Typescript can't infer types when using Proxy

Code

let obj = {
    prop1: function () { },
    prop2: 'hello',
}

let prox = new Proxy(obj, {
    get: function (target, name) {
        return 5;
    }
});

prox.prop1.

Expected behavior:
I would expect that when I type prox.prop1., I would get typescript suggestions for Number.prototype, but instead, I get suggestions for Function.prototype. prox.prop1 will (according to typescript) still be callable as a function, but in runtime, it will clearly be a number and will throw an exception.

Statically evaluate the proxy traps and determine the type of thing being returned to offer proper typescript intellisense.

The issue supplies no repository file or test entry point. Reproduce the provided Proxy example in a TypeScript editor, compare completion for prox.prop1. with the runtime result, and treat correct Number.prototype suggestions instead of Function.prototype suggestions as done.