I'm impressed!  Not many people are familiar with Relative ONI (RONI) which came out of that work that Rebecca mentioned in footnote #3.  For the last several years, CPC has monitored RONI on the side and it is located here:  

https://www.cpc.ncep.noaa.gov/data/indices/RONI.ascii.txt

As you can see, the RONI is 0.1C for MAM 2024, which is considerably different from the 0.7C value in the traditional ONI.

However, NOAA's official alert system is based on the traditional Nino3.4/ONI values, so at this point, we follow the traditional indices.