In theory, closer is better (slightly less ecu lag). I don't know if anyone has tried this in practice though. Some air flow meters don't like being too close to the throttle body (ie. less than 100mm) due to pressure back waves when the butterfly snaps shut.
But getting it closer might also make it more difficult to enclose the pod and get cold air to it which I reckon would be more beneficial on a highly tuned motor than having the afm close to the throttle body.