On each player's game
Unzip AzraelDragSpread into your Mods folder and launch without EasyAntiCheat. The server needs nothing, and players without it are not affected.
Sweep a stack across the slots
Players onlyNot yet tested in game
Spread a stack across inventory slots in one sweep. Pick up a stack, hold a mouse button and drag over the slots you want, then let go.
Left-drag splits the stack evenly. Right-drag places 1 item in each slot and keeps the rest on the cursor.

Unzip AzraelDragSpread into your Mods folder and launch without EasyAntiCheat. The server needs nothing, and players without it are not affected.
The stack is split evenly over the slots you swept. Odd items go one each to the first slots, so the whole stack is placed unless the slots run out of room.
1 item goes into each slot. The rest stays on the cursor.
Empty slots fill, and stacks of the same item are topped up to the stack limit. Slots that will get items show a highlighted border while you sweep.
Backpack, toolbelt, storage boxes, loot, vehicles and workstation slots (fuel, tools and inputs only take what they allow). One drag can cross from your backpack into a storage box.
A plain click and Shift-click work exactly as before. Locked slots and quest items in containers are skipped, the same as a normal click.