Regular Bluetooth 5.0 connection has a 145Hz polling rate, and connection to up to four devices by holding fn+1, 2, 3, or 4 ...

That stands for Grid Ergo Magnetic Keyboard, but I swear there are 48 ... Internally, there’s a Waveshare RP2040 Tiny and a mixture of Gateron Oil Kings and Gateron Yellow V3 switches.

The key development behind this type of sensor is realizing that nearly every mechanical keyswitch (Cherry MX, Kalth, Gateron ... a Cherry MX red and a (normal) mechanical keyboard PCB.