Interesting that Paul was unaware of the keyboard shortcuts even though it was mapped to search and playback functions. They use a RaspberryPi/Intel NUC style internals, hence the mouse on screen (they have a disabled WiFi adapter as part if this). Also, the Prime 4 uses a similar/same firmware so from this I decipher…
A version of the SC5000 firmware was already being tested on a primitive Prime 4 prototype back then and we had the keyboard enabled in the SC5000 firmware to get search on the prototype Prime 4 for testing.
Well that’s my totally made up theory and it could just be a total coincidence 