It IS a router, not a CNC machine.
That said, it can probably machine out the aluminium pockets if you take it gently enough.
Caution: much will depend on what aluminium alloy you are talking about.
7000-series - likely.
6000-series possible, maybe
5000 series and down: some grief possible.
You would certainly need an air blast and a pulsed misting system to avoid the dreaded Built-Up Edge failure.
Cheers
Roger