So I've been slowly working on the case, and since the Roller Assembly moves a lot of things around, I've gone back and have mostly been thinking about the bowden tubes for the cleaning string (and the LED wires). My original plan was to use a tape measure as a cable chain, but it seems that it would only work if the U is in the horizontal plane. Thus I'm looking at my options that eliminates the possibility of the bowden tubes hitting the PET film.
I've also been looking into how to hold the Z axis beams up. I've decided on trying out a 2060 and having that connect to 2 2020 beams to make an I-beam like shape. The case will go behind the rail to improve aesthetics. The 2060 likely would also hold each half of the case together. I am getting a bit concerned about space since I don't really want to exceed 605mm, but so far it isn't looking like there's going to be that much space for the cartridges (I'm putting in 4 of them) and PET rolls which will likely be at the bottom corners of the printer.