Hello @jtl !
The matrix scanning is entirely done using PIO hardware of the RP2040, it is very consistent in term of timing and gives very stable results during use.
The matrix scanning time is also very short (at 640us) and as the USB polling rate is set as 1ms you can expect around 2ms latency from the keyboard to the PC.
I already wrote one although it is very basic and not user friendly at all, it is just enough for me to look at useful data when troubleshooting.
It would need a lot of time to make a monitoring tool like for the xwhatsit (make by Pandrew), not a priority for now but maybe in the future ?
Best Regards,
Rico