Backup/rear camera and notifications toast

One smallish annoyance I have: when I start the car, I often am already seat-belted in and ready to go immediately. If I have to go in reverse, I do use the backup cam.

I've noticed that sometimes it takes several seconds for the car's Bluetooth to boot up, and when it does, it shows a toast notification from the top of the screen telling me what the current volume level is. It takes up a good 20% or so of the screen height and blocks the camera view considerably!

Has anyone else noticed this and found a way to disable those toasts while the rear cam is engaged? Or at least noticed it too and can commiserate?