The quickest way to drop full stacks of items in Minecraft (on a Mac) is to use Command-Q. But that keyboard shortcut is already set by Apple to quit the application. Is there a way to disable Command-Q to quit in Minecraft? I don't want to change the drop item keybind.
Mac likes to be annoying when it comes to game shortcuts, but you can override the Command-Q shortcut to use Minecraft's method of dropping items by using Ctrl-Command-Q. If you want to learn more about Minecraft shortcuts you can check out this website.
There's actually a forge mod for Minecraft called "Patcher" that allows you to change the drop modifier key in controls. I changed the drop modifier key to option and it worked fine.
So, I actually just made a mod for this. It's for Fabric and it's for 1.16.4+. Here's the link: Ctrl Q.
The mod is basically remapping the default Command key for Ctrl when dropping items. I myself had this issue, and it's only recently that I learnt how to make mods so I can code it. Have fun!
If you'd like to, you can remap it globally at the system level under Preferences -> Keyboard -> Accessibility. This answer has suggestions ranging from setting Cmd + Q as the shortcut for "invert colors" to "do not disturb".
Of course, this will change it for all apps though, and you'll still have Cmd + Option + Q for Force Quit, but that's obviously harder to accidentally do.