It doesn't take much for a cockpit to start to feel cluttered, especially on your mountain bike. If you're riding with a dropper and a front derailleur, your bars are probably about as full as you want them. When you add a computer into the mix, mount it onto the Gravity Cap Computer Mount for Garmin. The Gravity Cap replaces your existing top cap and gives you a low-profile way to keep your computer safe and visible while you ride. specifically had DH and enduro riders in mind when developing the Gravity Cap, but anyone logging data on a compatible Garmin can use the mount.
Just know that larger Edge models and steep stem angles won't get along great with the computer when used together; they're compatible, just not ideal.