The only thing I don't like about this article is it didn't talk about the actuation tech. It basically only showed switches with springs. My Void Switch design doesn't have springs at all!

https://github.com/riskable/void_switch

I'm typing on my AHEK-95 right now which has 95 Void Switches and a custom hall effect PCB (and custom firmware). It also has two custom analog rotary encoders (which is just a ring of six magnets over two hall effect sensors; the firmware is what figures out what direction the ring moved).

I sent one of my AHEK-95 keyboards to Chyrosran22 (known for his brutal keyboard reviews) and he reviewed it:

https://youtu.be/iv6Rh8UNWlI?si=9xGNm4jIDLFzx80c

One other thing missing in the article: Hall Effect sensors are temperature sensitive! My AHEK-95 has a number of features in the firmware to work around this (constant re-calibration) but anyone with other Hall Effect keyboards might have experienced it: Some keys seem to stop responding reliably after a while (usually a week or two in winter). This is because the temperature changed (enough), causing sensor drift. The fix is to just reset the keyboard (<1 second) which forces a recalibration but it can be annoying (my father in law has a Wooting keyboard that suffers from this after a few weeks if there's big temperature fluctuations at his desk which is right next to an exterior door).

Anyone with a 3D printer should print my Void Switches! It's a teeny tiny amount of filament (use PETG for best results) and only requires some 4x2mm magnets. I uploaded a model to Printables that has all the parts in one 3mf file: https://www.printables.com/model/233699-void-switch-fidget

Aside: Last time I ordered 4x2mm magnets, I ordered six thousand from AliExpress. That was after my last order of five thousand that I blew through quite quickly :D. I highly recommend ordering them in bulk like this because they end up costing about a penny each and they're useful in so many 3D printed things.