I’ve tried the stuff I can think of. I’m going to offload some of the stuff stored on it to an external desktop storage of some sort (which I have a separate thread for here: Advice on External Desktop Storage ). Not sure if this can potentially ease up the situation. It’s currently stuck with around 129 GB free storage.
…but the disk itself makes sound as if it’s about to exit the iMac as soon as it needs to do some work. So I kind of thing there’s some issue with it.