It’s been a long time since the last update for the Rockchip RK3399 series, especially for the Rock960B and C models.
A few months ago, I found a stable kernel version 5.10.66 that works well on my Rock960B and C models, providing full support for Broadcom SDIO Wi-Fi and Bluetooth.
Debian 12 will work fine with the latest Rockchip RKBIN (bootloader fixed byte alignment issue).
I will update my last modifications on GitHub soon.