> In many cases, we chose to exceed existing standards for tap target size, color contrast, and other important aspects that can make interfaces easier to use. So now even more space is wasted, making interfaces harder to use, but yes, the less important metric "how much time does it take on first use to spot a button" will shoot through the roof of you make the button full screen width (10x faster!). Thought it will…
By making the Back button larger and more prominent instead, participants would be able to spot the button four times faster. I suggest to reduce the size of the Send button.