Pulled the fuse barely a week after owning the car. It's definitely not too loud and I can hear it while cruising but it's certainly not annoying
My neighbors are used to hearing loud cars in my driveway so that's not an issue.
Can you be more specific about warranty concerns? I can see them refusing to replace the valves/mufflers if anything broke on them but I seriously doubt preventing the valves to close would cause an issue with the mufflers that would require replacement.