Same for me! I was sitting around, bored this morning so picked up my very old OP2 and tried to update to lineage Oreo. Somehow ended up bricking the phone. Found this thread and gave it a go. I normally use Linux for everyday computing, but I do have another SSD with Windows 10, 64 pro version. Fired it up and followed the instructions in the OP .... I did have to repeat a step or two along the way, but overall a pretty easy guide to follow. After it finished and went through the initial setup, it prompted to update to latest OOS, which I did. Then i unlocked the bootloader, installed latest TWRP and finally magisk.worked like a charm on Windows 10 x64 PRO.
You just need to know what you are doing.
Thanks alot m8
Thanks so much for the guidance!