I often go through my inventory for various purposes: to find a weapon for a new build, a crafting base, etc. I imagine many players do.
Marking an item as favorite is helpful, because (in addition to preventing accidental deleting) it allows for marking crafting bases or whatever for future use.
Similarly, I would like to propose a mark for discard and/or sacrifice feature. When marked, it does nothing besides applying a tag, just like adding to favorites. When actually discarding or sacrificing items, the marked items could be preselected.
Or the option to hide everything except the items marked as favourite.
Reason is, I still have tons of items I can’t even sell because I’m at 25M and nothing to buy with it, and I still grab every item with a perfect distribution I find at the shop.
Now if I just want to change my equipped weapon I have to scroll through all this.