Totally misread the post so I will try again...
I recently made a large 15mm birch ply /melamine bookshelf myself - though I did use the 5mm Dominos as they are still 1/3 of the material thickness. I centered the Domino on a piece of scrap though I have sometimes used the 16mm preset hard stop for 15mm material which works fine as long as you remember orientation and inside/outside on carcass and up/down on shelves.
If you start by making the actual carcass which I am sure you know how to do - you can just make a template by using the bottom end of the carcass and do both sides of holes the same way - starting from the bottom.
Say you want the space between the bottom to the first shelf (underside) to be 200mm I would go about it this way, assuming you have centered the holes in the shelf:
The DF500 is 10mm from the base to the center of the Domino so you need to factor that in:
200 + 7.5mm to center is 207.5mm - 10mm for the baseplate so make a piece of scrap 197.5mm long, square and same width (or wider) than the carcass and simply place it against the bottom. Sidewall flat down and bottom in place. Place your spacer down against the bottom and clamp it in place and then you can reference the Domino flush against the bottom and against the edges or other markings.
If you run the Domino on the 16mm hard stop and plunge the shelves from the top side you will be off set and you need to factor in that off set in the set up of your spacer piece.
Once the first one is done you simply move the bottom piece (or shelf) along and repeat the procedure. This will give you perfect same spacing with just one spacer and one shelf moving along all the way. Repeat for the other side, remember to start from the same side!
EDIT:
If your carcass is wide so the bottom is "wiggly" when carcass is laid flat on its side just make a short piece the same width as the carcass from a piece of scrap or an off cut. Remember: all you need is that reference to bottom by using same thickness/material as the "true bottom".
On these I ran the pocket calculator and worked out the uneven spacing and made all cuts in a row with different spacers. It was then glued up and shipped out in two pieces, it was 305 cm tall with the bottom cabinet added so too tall to ship out in one piece.
This was 16mm Walnut veneer mdf with edgebanding. Same procedure though.
In the picture you can see the spacer piece with the measurement scribbled on it (to make sure I did the math right).
