The universe is just one enormous 'Soul Filtering machine'

[Angrboda]

So, your 'god' is able to design a dimension, where free will exists, and humans have free will, yet are unable to do evil. Why didn't he just create the dimension we currently inhabit, with humans having free will, yet are unable to do evil?

But you can't get to the "heaven" dimension without first having experienced this dimension. As you pointed out, a filter has already been applied. The flaw in your logic is using a generic human when clearly the dimension of "heaven" is filled with specific humans having specific experiences that led to them being there.

You seem poorly read on the concept of free will. Libertarian free will implies that a person can choose to do any alternative available to it, regardless of past events. Your objection that the persons in heaven share a certain past is irrelevant. Your objection is moot.