Hi folks, thanks to this thread and all the people invovled, i was able to bring back my bricked OP8Pro. I did had to do some voodoo stuffs to get it running. For anyone who comes across this post, be patient and persistent you can do this.
So, i tried with Windows 10 and was not able to get the Qualcomm drivers to work using usb3.0, OP8pro cable. Tried a lot of forum posts and ideas, nothing was getting me to flash it up. All i had was unlocked bootloader, nothing else. After several hours, took my old Windows 7 device and connected the phone to a usb3.0, OP8pro cable and without internet. Wow, it automatically installed Qualcomm 9008 driver and was able to start msmtool, connect to device.
Wierdly, msmtool's progress started to stuck at 'Downloading super.img'. After waiting for 900s, decided to press vol up and power button which got me to bootloader. Then again pressed vol up and power button to switch off. Immediately pressed vol up and down (NO power button). All these while phone was still connected to laptop where msmtool was still running. MSMtool detected and started to continue.
Then again it stopped with the progress. So weird was: progress bar stops at 25%, i do the power off and edl, msmtool continues to 60%, stuck, redo power and edl step, msmtool 90%, stuck, redo...and so on. I had to do this more than four times at different stages, few times during super image download, few times during userdata or whenever the progress was not happening. At the end, the download was complete and now device back to work.
OP authors claim of 300s is almost accurate and mine was EU version.