Been using demucs for a couple of weeks now, mostly taking my early produced music which I have since lost the project files for and giving them a remix and update. Gotta say I have been blown away by how good demucs is. I installed it following the repo instructions and then created a zsh alias to run it with any file name. Eg $ai_split mySong.mp3

Wait fifteen minutes and out pops four stems, flawless so far, even been messing around with mainstream tracks and using ableton with warp applied to quickly build out remixes. Demucs is going to be /is already a game changer!