I've been exactly where you are, and can only say that despite it being maddeningly frustrating there is still always a way. It might require melting off a chip and soldering a replacement one on (with significant loss of data)

https://xdaforums.com/t/poco-f1-bricked.3968436/#post-80252328

You tried removing the battery panel and connecting the two test points to force EDL mode?