I think the best cuts on Kaizen are with galvanized pipe fittings if using horizontal storage (But food cans can also be used) that have a somewhat sharp edge beveled from the inside rim to the outside with a grinding stone wheel on a Dremel , and T' joint on the end of that to give you a hand hold to press and screw the pipe back and forth to cut. I secured a layer of electrical tape to one end of the pipe so the "T" joint it press fits on the end and can be removed to push out the die cut piece with my finger, you can dig them out if you want though. Kaizen was very easy to cut with a sharpened pipe, and the cuts are very clean when done right.
The galvanized pipe holds the edge better than copper pipe fittings only drawbacks are they get dull and have to be resharpened often, try to get pipe fittings that are within the same size of the eps either exactly right or a little smaller but not by much 1-2mm at the most so you get a good fit, if the pipe is too big in diameter the eps will have a loose fit, if too small it will have a too tight fit. For my HD60's I used a 2" pipe and T joint, for my 40mm-32mm Plossls I use a 1.5" pipe (I think that's what it was), if you need a custom fit you'll have to trace the exact shape you need for that accessory.
I use Graph Paper to make a template to the exact size of my box or build it up by taping paper together at the lines for bigger cases, then I use the EP eye lens caps (if they are about the same size as the EP body), and use each cap that represents an EP placed on the paper evenly spaced until I get the perfect spacing/ layout using the graph lines, for me I used about 1/2" (two rows) between EP holes, then I trace the caps and make the cuts with a sharp Exacto blade, I cut out entire corner for square cuts that will hold any filter box cases by measuring them when stacked together, that way I don't have to waste any space.
Then once the layout is perfect, I tape the template that is the size of my case to the foam and use a carpenters roofing square and a utility blade to make shallow cuts about 1/2 " deep at a time until it cuts through , this helps keep the cut standing straight, and I cut foam block that fits inside the case about 1.5mm larger on two of the four side so the foam has a nice strong hold when pressed inside the box that doesn't have to be glued with strong glue I just use some double sided tape around the corners on the foam to help hold it in so when removing a EP it doesn't lift the foam out. Then I cut the EP hole by centering the pipe in the center of the cut-out template, and use medium pressure so you don't get the holes tilted, which can happen if using too much force and not paying attention to how straight the hole you're drilling is by checking it from several angles every 1/4"- 1/2" depth drilled. This makes a very clean and symmetrical looking case layout.