PC The Division 2 – How To Exit To Desktop From In-Game

I solved this problem, at least on my multi-core machine:

Start the game, wait until the main menu hangs, bring up the Task Manager (i.e., press Ctrl+Shift+Esc). In the list of processes, search for the image: "DX2Main.exe". Right-click on it, and select "Set affinity", and select only ONE CPU core. It doesn't matter which one is selected. For me, there was no need to restart the game as the hanging state was gone.

Here are some more mouse-trap applications, like CSMMT which Shaun's answer mentioned, that trap your mouse cursor in one screen of a multi-monitor setup:

• MouseTrap
• MouseJail
• MurGeeMon (supports Lock Mouse Cursor On a Monitor)
• Script for AutoHotkey

I can't vouch for any of these, but you can try them out. You can also search for more with keywords "multi monitor trap mouse" or similar.