If you are worried about the aluminium, two thhoughts
1 Aluminium is likely to have a higher coefficient of expansion that cast iron, so applying as much tension as you dare and then applying heat away from the hub will allow the heat to seep into the hub before thew shaft.
Hopefully it will pop off.
2 An alternative is to place a bearing extractor. (The two piece type that you clamp together with a couple of bolts ), so that the load is applied to the hub not any spokes by your puller..
On one occasion, despite applying heat and a LOT of tension, the thing would NOT come off. As I walked away despondent, there was a bang and the brake drum and puller shot across the drive and into the flower bed.
HTH
Howard