This mod allows you to drop items in a batch.

Shift + Q = Drop the item under the cursor.

Shift + Double-click Q = Drop all items of the same type and name as the item under the cursor.

(It's fine even if the key you've set isn't Q!

I realized later that it seems you can also do it with Ctrl+Q.

https://youtube.com/channel/UC7DGSVEgrreHJThpIW6sy1A?si=79e_turnPd46aEbR