Extended the depth of the 3 body pieces by 25mm. I was not able to place the original HAL-9000 flat on a table or against a wall due to the protrusion of the LED/momentary switch module from the back of the body, which this remedies.
Added access holes for wiring between the top and middle compartments of the body. I used this to add a second microcontroller (QT Py ESP32-S2) in the top compartment wired to the Feather, but you can use this for any other mods that require additional wiring/components.
Added 2 versions for the bottom, one with just the extended depth, and one with a hole large enough to mount a headphone/TRRS jack (https://www.amazon.com/gp/product/B073H7L59X). I use this to provide a way to use the button to trigger external events to connected devices over UART.
Also provided the STL files for the case I used for the QT Py. I just mounted this in the top compartment with some VHB adhesive tape.