since you are on v9.0 of Luma, you have successfully upgraded A9LH to B9S
Wait, I am? I'm going from A9LH to B9S, so if I did NOT complete that part of the conversion guide, where I get safeb9sinstaller to launch: 1. Boot your device while holding (Start) to launch SafeB9SInstaller, 2. Wait for all safety checks to complete 3. When prompted, input the key combo given to install boot9strap.
....then how am I on B9S?? How do I know i'm not still on A9LH still? I was able to use Luma on A9LH, so that doesn't really help show me that somehow B9S installed itself without prompting/input.