Tray System for drying Silica Gel in a Creality Space Pi Filament Dryer or a Creality Filament Dry Box 2.0

The generic purpose of this tray system is to regenerate silica gel with indicator, after losing its absorption capacity, in a Creality Space Pi Filament Dryer or in a Creality Filament Dry Box 2.0 (this was suggested and modified by @lollo1188).

It's inspired by Stephan's video, from CNC Kitchen, where he discuses drying desiccants.

 The specific goal is to augment the surface on which the silica gel can be exposed by stacking multiple trays thus increasing the quantity that can be dried in one session.
 
 The tray's tessellation, used to allow the water vapor to dissipate, is calibrated for spherical silica gel with a minimal granularity of 2mm - for a lesser granularity you should test for leaks and adapt the model; the source code, in OpenSCAD using BOSL2, is provided.

A document is also provided where I discuss in a little more detail the motivation, printing, assembly and usage.