Black Shark 2 Team - A Big Disappointment
I've been using the phone for almost 4 months already. The hardware is good but the software is terrible - it has a lot of bugs, issues, and inconsistencies. The Black Shark 2 Team seems to be negligent in addressing software problems, and rolls out updates with more bugs in them!
Regarding the kernel sources and bootloader unlocking, they haven't released the former, and prevented the user to do the latter by totally removing bootloader unlocking capabilities of the phone.
If you're reading this, and are planning to buy one, I discourage you to do so. Better get a Red Magic 3 or Asus ROG Phone II.
Shoutout to Black Shark, Asus has just released bootloader unlocking tool and kernel sources for their two-week old ROG Phone II. SMH.