I have doubts because JVC cooperates with RITEK, and discs for the Japanese market (Victor) are made in Japan, so why would they need to manufacture discs at CMC?

No, they are definitely legit. :)

Victors products made in CMC? Do they even exist? Could they be counterfeit?

Victor 1-4x Printable BD-R
 

Lite-On iHBS212 2 HL05, 15.35 GB burned at 6x speed

sold as "Victor 1-4x Printable BD-R
MID: CMCMAGBA3 (000)
manufactured in Taiwan by CMC Magnetics

Thanks to Dr. Gough Lui (https://goughlui.com/) for providing the media for testing.

https://forum.cdrinfo.pl/attachment....1&d=1772312124