yes you can push much harder in alum. however your talking small endmills, so it really wont be close to your 5/8 endmill feeds and speeds. Unless you have 15k-20k rpms.
the best cutting alum 1/8 endmill out there is harvey tool( ones made for alum). it rips the alum out.
the 1/8 mill doesnt have the flute clearance like a bigger 5/8s , make sure you use tons of coolant