Is it possible to show multiple toast messages in SF1 stacked?
When I fire more than one showToast event it displays one after another. But I want to display them all at once in a stacked layout.
No. The toast framework is built into the app, so there's no way to customize its behavior. Additionally, this wouldn't be very mobile friendly (imagine getting three toasts and your entire screen's obscured). Instead, you should consider using only as many toasts as you need, which would ideally be fairly infrequently. Of course, if you don't want to use the toast framework provided by SF1, you could build your own, but you should consider the consequences of your actions on a mobile device. It doesn't take more than 2-4 toasts to completely fill a 5 inch screen.