Stackable Vertical Spool storage

As everyone else in this 3d printing hobby/business, we face the same issue “Storage”. I was no exception of course! :) I have a small room ("mancave") dedicated to my hobbies and I'm trying to fit everything needed (and maybe not needed) inside, filament storage being one of the most frequent struggles I encounter. I tried to use every bit of space to store filament but still not enough! Then, in a moment of inspiration, I've spotted an unused space behind the door and it sparked an amazing idea. I quickly went online to look for a trustable vertical spool storage, clearly someone had the same need, but no such luck. So it became my top priority to design some kind of vertical storage to make use of that dead space. After a few trials and errors I've came up with this design which proved sturdy and reliable. The one i put together has 26 trays, which equates of 1.95m tall and to fix it to my dry wall I've used 6 wall screws/plugs, two near the bottom, two in the middle and two at the