The old steel frame dent removal trick might work on your Al frame as well...
Get a block of hardwood, like oak, and drill a hole in it the same size as your frame tube. Cut the wood in half so there are channels in each piece. Clamp the blocks with the channels over the dented area. (assuming there are no cable guides in the way) As you slowly tighten the vice, twist the frame so that the dented tube is moving back & forth in the hole. Keep tightening and twisting. Eventually, most of the dent will be pushed back out. The rest you can fill with a little Bondo.
Just an idea. Good luck with that!