You did not tell me what the battery voltage was with the engine OFF, with ignition off..
With 13.70 volts at 1000 RPM and 12.52 volts at Idle,, what is your idle RPM. You gained almost 1.25 volts going from idle (unknown RPM) to 1000 RPM. Shouldn't your idle RPM be near 1000 RPM.
Do you have any real problems (battery goes low or dead after riding) other than what seems to be a problem (dash volt meter shows low above idle)
Entry point #10 says "checked battery holds a charge". How was that determined.
Some of these facts are not adding up.