That's what I did joey..I milled .500x..250 holes every 1"..the delrin mounts to a 1x1 solid aluminum bar..
But, it doesn't bend like the black stuff that the other guys use..this stuff is white....
It is not that bad. It just needs more to make it bend than you had envisaged.
The more slots and clamping, the finer the changes that can be made on the bar.
Keep in mind ,the position is going to be the resultant of the two materials when clamped together.Plastic and Ali is not as solid as plastic and steel.