The CurseForge page says "Shift+Right-Click with empty hand: Open a UI to see exact item counts and manage applied upgrades." This does not seem to be working for me. Nothing happens, and nothing is logged as far as I can tell. The setting is enabled in the config file.

Minecraft 1.16.1
Forge 32.0.69
StorageDrawers-1.16.1-8.0.0.jar

Well, it's working now. No idea why it wasn't before. Woops.

I figured it out. I had a shield equipped. I guess there's not really a simple workaround for that.

Why is this closed? This is a valid issue that wasn't present in earlier versions afaik. And it's not like offhand mechanics are new.
Also happens with other items like torches in offhand, by the way.

If it's not intended, then it's still an issue I guess. I haven't used previous versions, so I don't know what the expected behavior is.

This is an issue that has (in a minor way) irritated me for a long time, so I'd love to see a fix for it. To be clear, though, it has been around for quite a long time, it's not new to 1.16.1 by any means.

Quite a few mods haven't dealt with the "items in offhand interfering with right click mechanics" issue. Another prominent example is Botania, where there is a mechanic to remove the item you last placed on the runic altar or into the petal apothecary by shift-right clicking. Anything in the offhand interferes with this mechanic.

The problem is that right clicking activates the offhand (usually a shield). Minecraft seems to intercept this behavior with regular (non-shifted) right clicking, e.g. you can open inventories, doors etc. while holding a shield. Shift interferes with this behavior -- shift-right clicking always puts up the shield / places a torch etc. You can't interact with vanilla inventories with a shift-right click, either.