I just replaced my Aluminess front bumper mounted hitch reciever with a Reese Heavy Duty frame mount receiver and was elated to see that there was no modification required to the bumper for the new receiver! Not sure if this applies to your question
I posed the same question to Aluminess, and there response was:
Hope all is well, unfortunately that curt receiver hitch will not work with our Aluminess front bumper set up. We have our own front 2" receiver it goes for $100.00 and it bolts on to the bottom of our bumpers.
Not sure if there is something specific to the Curt or if this is a standard answer. I will update if I move forward with Aluminess.