You say you have tried this "on multiple tablets", but you only mention the 740. What other tablets have you experienced this on? Is it possible you're just unsatisfied with the 740 itself, and not the iFly software? The 740's screen resolution (800 x 480) is relatively low compared to iOS and most Android tablets. My Samsung Tab S6, for instance, has a 2000 x 1200 pixel resolution, and thus can produce a much sharper image. That said, most users find the 740's screen to display adequate detail.
Is the screen clarity issue obvious enough that you could take some good photos of the iFly screen and another EFB app showing the same plate at the same size for a side-by-side comparison that illustrates what you're seeing?