I also can confirm that new version of Android-app works writing RFID labels for new CFS firmware.
Yes, it is used only to find out default filament type and, even more important, the color.
For non-CFS users they can identify still the spool on the RFID reader of the K2 on the side of the spool holder.
The RFID tag is not used to track the usage of filament (even if it would be possible to do it because you can access this information on the mainsail/klipper interface of the printer which is done also by CPV6 where you can see some infor as well instead of directly on printer).
It helps the CFS to calculate the available filament on spool becuase when the filament is loaded it measures how fast the spool spins (measuring time between passing of RFID) and then calculating with the spool size (which is written on RFID) the available filament amount to show. This works only in CFS of course.
Anyhow, I create for all filament (types/vendors) my own profiles where I set the right print temp, PA, max flow rate, flow rate and bed temp … and I need to change in the slicer the filament type from ‘General …’ to whatever it is.
I have > 100 filament rolls from ~15 different vendors and seldom use normal PLA(+) other than for fast prototyping but even then I use for example Elegoo Rapid PLA which prints faster than Creality Hyper PLA @ half of the price.
I have also some SUNLU/JAYO filament (JAYO & SUNLU are the same, JAYO is just the 'cheap brand and SUNLU the bit more expensive original brand) and I may test some newer filaments like the high speed matte PLA/PETG or so because I hate the normal glossy PETG look.
My experience is that If I get very high discounts for some filaments it most of the time does not fulfill all promises and they just clean off stock!