Digital/Analog Grounds

Internally, (on EMU Pro 8) what is the difference between the C29 Analog Ground, the A20 Digital Ground, and the B9 “USB” Digital Ground? Are they isolated from each other in any way or is there something special about the Digital Ground (or, if I’m not using the USB logging on ECU, the USB Digital Gnd?)

I ask because I am trying to decide if I need to splice the single Analog GND across 100% of analog circuits or if it would be possible to use the USB Digital GND for the Throttle Body TPS sensors without any negative consequence.

All grounds are connected internally but routed in different ways to separate digital, analog, and power currents.

Electrical noise can significantly affect only analog signals, and it can come from digital signal switching or high currents for loads. If you connect an analog sensor to the digital ground, there might be slightly more noise in the reading of that sensor compared to using an analog ground. You could connect slower and less critical sensors there, like temperatures.