The hazard warning switch is accessible without removing your phone or the mount.
Just Curious.. does your holder with arms work well? How difficult is it to attach and detach your phone? The magnetic holder makes it very easy to attach and detach our phones. I looked at both models and finally chose the magnetic one without any real reason.
I have an old iPhone 7 Plus with a fairly thick case. The grips on the arms can be bent to fit the thicker case, but I haven't had to do that. It's a little fiddly to remove the phone, but not a big deal.
What may not be clear is that the arms adjust. When you lift the phone, the arms spread to release. When you set the phone and put weight on the lower support, the arms contract to grip the phone.
I didn't want to use the magnet because I will be upgrading my phone soon and I wasn't sure if a magnet would interfere with wireless charging. The back of the cases I prefer is also not flat, so I'm not sure how well a magnet would stick.