Don’t be in a hurry.
A CNC Engraving Machine / CNC Router can cut aluminum. The price you’ll pay for success is slowing things down. Note that we don’t mean to literally slow down your feeds and speeds, but your overall Material Removal Rates will be less than what can be achieved with a purpose-built CNC mill. So relax and let the machine do its thing. At the very least, a good sized CNC Engraving Machine / CNC Router can fit a lot more material on its table than most any CNC mill. Load it up, press the green button, and walk away.
Watch cut depths and slotting–they make it harder to clear chips
The deeper you cut and the closer to a slot the cutter travels in, the harder it is to clear the chips out of the bottom of the hole. Make more passes to cut down to required depth and to open up the shallower depths for better access.