I just tried to use this method and it bricked a Note 8 N950U1.
Here's what I did:
I had V7 bootloader first, so I flashed a V8 firmware (BL, AP, CSC) and it booted up fine to the OS.
I was having some issues with Odin so I decided to turn on USB debugging used ADB to boot into download mode (adb reboot download).
I used the N950 combo firmware to flash under the AP tab, unchecked the auto reboot.
The flash went through and said PASS and I went ahead and manually rebooted into download mode until....
nothing happened.
Just shows a random bar fast flash only when trying to get back into download mode. Will not power on or show recovery, bootloader, OS, or even charging icon.
I work at a phone repair shop so I decided to open the device and unplug the battery like was said on this forum, but unfortunately still no success. No QL download mode either. Not sure if I did something wrong or just one of the unlucky ones.