Currently, in FS, if a drawer is locked to an item, but that item happens to be empty, it is impossible in FS to know what is locked in that drawer, period. You can not see it in ANY 'what am I looking at' type mods, nor can you even see it in your own GUI for the drawers, instead, even though the drawer is locked to an item, in the 'what am I looking at mods,' NOTHING shows up, and in your own GUI, it shows EMPTY, instead of showing what item it is locked to.

This is not user friendly, even in the least, and I wish it would show in 'what am I looking at' type mods "abc item, qty 0/x" in whatever format exists for that mod, and at the very least, I would expect your mod to show what is locked to said drawer when empty at the very least in your own GUI.

You can see what is locked inside empty drawers in 1.21, what version are you playing on?