First thing is to confirm it REALLY is the stator!
HUGE job on an R3 to replace - needs the engine to come out - no kidding! - So better to be sure.
Most shops end up 'guessing' at the stator being the problem without really knowing how to confirm - bad enough on most bikes, but major project and cost if misdiagnosed on an R3!
VERY simple test - you don't even need bike running, or to measure voltage to check stator.
disconnect the R/R;
Set Multimeter to Resistance (Ohms) scale;
(Note the reading when the probes are not connected to anything; then touch probes together and it should go close to '0' - first reading is 'open' circuit and second reading is 'short' circuit)
Now set one probe on ANY one of three terminals in connector going back to the stator;
connect other probe to engine ground.
(note carefully that we are not measuring BETWEEN PINS - we are measuring from ANY ONE pin to Engine ground - it does not matter which pin you select as they will all read the same, whether that be all good, or all bad)
If it reads 'zero' then that is short circuit and indeed stator is toast;
If it reads 'open' (typically 1999 or similar depending on meter - same as if probes not connected to anything) then the stator is 99.99% to be good (in which case likely the R/R that is the issue)