I am familiar with twrp on other phones and see it for the S21. What I can't seem to find though is a stock Android (not One UI) rom that I can flash. I am running Ruthless Launched on One UI 4 / Android 12. It just doesn't do it for me. I was much happier with the Pixel layout so that's what I want to do on my S21. Can someone point me in the right direction please?