This remix of @CaptainObvious' "Small storage system" changes the design of several parts of it:

1. It now accommodates two double-height drawer + 1 normal height drawer (remix from CaptainObvious' [https://www.thingiverse.com/thing:3772900](own modified design) to accommodate one double-height drawer and 3 normal height drawers)

2. The rings at the sides meant to hold adapters for shorter drawers are removed to save material and sleeker design

3. The right & left side and top/bottom parts of the 5x4 version are changed so that their bottom, including the screw holes, mirrors the upper side of the 4x3 design (their top not being changed means you need to print one top/bottom part from his original design for the top and this top/bottom part for the bottom; originally the top and bottom parts were identical). This makes it possible to seamlessly stack a 5x4 rack on top of a 4x3 rack, as long as you make sure to scale the respective parts of both versions to be the same dimensions (you then need to scale the drawers and the boxes inside by the same factors as the rack they're gonna be in).

-> Just print:

1. CaptainObvious' original design of the 4x3 rack
2. the (scaled as described above) rear and one top/bottom part (for the top) of their original 5x4 rack design
3. the two sides and one top/bottom part (for the bottom) with my changes, from here (with "_stack" at the end of the filename)
4. plus the drawers and boxes from his design (scaled by the same factor as you had to scale the 5x4 parts, as described above).

The third change is achieved by:

1. moving the screw holes of the side parts
2. adding tiny cavities to the bottom part to make sure the screw can go all the way in (because the moved screw hole is now located very near the edge)
3. adjusting the outline of the upper rack bottom part's cavity meant for fingers to be able to draw out a drawer so that it matches the outlines of the lower rack top part's cavity
4. increasing the thickness of the side parts' outside-facing sides so that it's flush with the lower rack's side parts despite different scaling while not decreasing the inner dimensions meant to hold the drawers

Attention: The rear part of the upper rack will not be entirely flush with the rear part of the lower rack because I didn't repeat step 4 here since the rear won't be visible.

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I also included the design for a 5x4 rack for 2 double height and 1 normal height drawer without the moved screws (without stack at the end of the filename) so you can print those as a standalone rack (just print all the other parts from his original design).