So I recently made one of these for myself. However, I changed the configuration a little bit. I didn't utilize the notch, as I felt that put the "nose" of the ZX a little too close to the hard edge of the case. So instead, I arranged it at an angle with the "nose" in the bottom corner of the case, the flat side of the "tail" where the two compartments are (facing "up" towards the handle), and only cut out enough foam to nestle the instrument fairly snugly in that position. That way there is foam protection on all sides and if it's bumped, it's got suffiicient support to absorb the impact in any direction. The weight of the ZX is therefore also supported by the top surface where there are no triggers, when the case is being held by the handle.
One thing I've noticed is that the lid of the case (which is also made of styrofoam like the bottom) is rather firm and I have to sandwich the ZX pretty tightly into the case. This raises a bit of concern; while it means the ZX is held in place and can't move much, I'm a little worried about how much pressure it's putting on the triggers. It only comes in partial contact with them; the specific place where it doesn't have clearance is where the lid juts out a bit to seal up the two compartments when the case is closed. I'm just hoping that it won't cause any problems and that the styrofoam will settle in soon enough so that it's snug, but not so tight.
I also replaced the "stock" strap with a nice padded lambskin one with softer rolled edges. While I liked the stamped logo on the original strap, in my opinion, it's about the same quality as the ones that come with Guitar Hero guitars, except it has to hold something 7 times heavier. I'm not a big fan of having a chafed neck and was a little surprised that the Zendrum came with something so flimsy and cheap.