The depth of my Auto-disk is .452" A piece of plastic that thick and 2.3" wide will slip into an auto-disk in place of the disk. Once you drill a hole in it just the right size and cut a notch to accommodate the actuating arm you will be able to make your own auto-disk insert of any size you want. If you make two half-height inserts, leaving one stationary and the other sliding back and forth you have just made a micro-disk.
It is something I have been working on in my spare time.
I too would be interested in this. I have considered upgrading to the Pro Auto Disk for all my regular larger loads, and trying to modify my existing Auto Disk measure. I was thinking of grinding down the hopper mounting bosses and the charge bar to create a "half-disk" measure. Same effect as a micro-disk.
My hat is off to all you guys who can get this measure to throw a consistent 2.9 grain charge of Unique.