A minor thing, but given Factorio's level of polish it may be worth reporting.
What I did:
- Open the Assembler UI, try to fill a single item into the input slot. I accidentally used the "Drop Item" key (Y) instead of the "Cursor Split" key (RMB), because that's the key I had used to insert single items all through the burner phase.
- The Item dropped on the ground at the location under the cursor, which was obstructed by the window.
- If the cursor isn't targeted at the ground (and the ground isn't even visible), then there should be no interaction with the ground, i.e. the item isn't dropped.
- Better yet, the key should act as a "place one item" key when hovering input/output/module/fuel slots or inventories.