I noticed that the ‘Opple Home’ app was recently updated on Dec 29, 2023, and here are my observations of the updated app.
The R9 from my CSP2323 6000K (Wurkkos TS10) has dropped further down to 40. In the previous version of Opple Home (Oct 2023), it measured around 60. In the Opple Smart Lighting app, it measured 83. I am not sure if this is actually getting closer to the real R9. The numbers now seem all over the place, making it challenging to have some level of confidence.
On the bright side of things, I did not notice major changes from the measurements from my Nichia B35AM. It reports Ra >90 and R9 about 80, which was expected.
However, when I tried to measure my Wurkkos COB keychain light (cheap 6500K low CRI LED), it did not give any R numbers. In the previous version, the app was able to produce low Ra and negative R9 as expected, but after I updated the app to the current version, the measurements of R numbers are no longer possible.
I personally think the previous version was more useful. At least, I could easily distinguish a low CRI LED, but now all I see is a bunch of missing numbers.
I cannot comment on how the measurements may have become more accurate, as claimed by the app developer, because I do not have a good reference point to compare my measurements with. However, judging from the measurements of a limited number of LEDs I have at the moment, I don’t think they have become more accurate.