I'd like to add my vote for a button to arm all cameras at once. Having 8 cameras, it takes some time to arm all of them. Having a single button to arm all cameras would be most welcome!
There is an easy way to do this via the app already that you may not have already discovered, which is via the Schedule Setter. If you set up schedule presets then this really does become almost a one-tap operation in the app.
A big DUH on my part, thanks Ben!