Long story short, I was able to do this in the past, but I had to uninstall and reinstall Display Fusion, and I can't remember how I was able to do it.

But how it worked is that I would open the browser or Discord on my secondary monitor and press a hotkey combination, then a noise would play, then I'd open the game in fullscreen on my primary monitor, and put in the same hotkey, and the same noise would play. Whenever I use the hotkey again to disable whatever it is it did, a different noise would play.

But now, I can only have one window open at a time. If I have the browser open, then I open the game, the browser window disappears (I think it technically goes behind the game window). And the only way to bring it back is to tab out of the game, which minimizes the game window.

Sorry for the lack of detail, I hope this explains what I had set up. Do any of y'all know how to make that happen again?

Edit: I seem to have fixed the issue. There's no soud effect now, but I put the game in borderless windowed mode, and I have a hotkey that unlocks the cursor from the window, so I can still interact with the browser. But I'm pretty sure I was able to do the same thing with fullscreen games, and I think that the hotkey I had did something to keep both windows in focus, but I used the free version.