RE: 1024 Resolution
It means the TX will split the full possible range of its travel signal into 1024 spots. The Rx then has to convert that back to a PPM signal for the servo. The full travel range of a servo is 0.9 to 2.1milliseconds, a range of 1.2ms or 1200 microseconds. So for every 1 point of the 1024 resolution, the Rx output to the servo can change 1.17microseconds. Most digitals and some good ordinary servos will respond to a minimum of 1 microsecond so they will respond to the 1 point step of the 1024 PCM. Most ordinary servos have a deadband of 2 to 4 microseconds so will take a few more steps of the 1024 system before they respond to a change.
When in the default travel of 100% a Tx is not sending the maximum travels, it is well below it. For example, JR allows up to 150% at which point it reaches the full 1024 positions, its default 100% travel uses 683 of the 1024 positions. Futaba uses a slightly different mapping, 100% travel uses 731 of the positions which is why Futaba’s max travel is 140%.
The resolution is always there, regardless of using expo, rates etc. These just affect the curve mapping the stick position to the output value, but the resolution of the output value remains the same. Each brand or type of servo uses a different max rotation in degrees, so you can’t say precisely that one step is so many degrees. But a typical servo would rotate approx 100 degrees at max, so each of the 1024 steps would equate to around 0.1 degrees.