I like the straight design of Wall-mounted Prusa Drybox with humidity sensor. It lacks some features like auto-rewind and support for PTFE tubing though. So I added the following:

Support for Integrated Auto-Rewind spool holder by VincentGroenhuis https://www.thingiverse.com/thing:3781815 as first done by rpgweb https://www.prusaprinters.org/prints/58523-standalone-drybox-with-auto-rewind-support
Compartment for desiccant/silica packs
Filament feed through PTFE tubing attached with a PC4-M10
Gasket - as I noticed that humidity was still an issue with sensitive filaments as TPU or Nylon

To build this you need

Vincent Groenhuis parametric auto-rewind system (minus shaft)
100 mm shaft by rpgweb (see files for a combined 3mf)
Top & Bottom housing (needs to be rotated sideways to fit print bed)
Lock
Gasket is optional
Screws: 1x M3x5 / 1x M3x10 / 2x M3x30
PC4-M10 fitting
PTFE tubing

Top and Bottom parts of the box should be printed with PLA for minimal warping. Gasket printed with TPU. Everything printed at 0.2mm layer height without supports.

Take care to screw in the fitting perpendicularly to the thread! It might be damaged otherwise. I inserted an Allen key through the hole for proper alignment.

Original build instructions https://blog.prusaprinters.org/dryboxes-and-alternative-spool-holders-not-only-for-multimaterial-upgrade