In flight it would be useful for situational awareness to show the closest vertical edge of controlled airspace below and above.

One easy way to show this would be as text field with the others (like ETA, altitude, ...).

A more advanced version would be a stylized vertical profile at the side of the display in form of a vertical bar with small horizontal markers showing the vertical airspace structure above and below the current position.

A related improvement would be to highlight the closest controlled airspace edge in the menu that pops up when holding the finger on the chart on the iPad.

The "more advanced version" you speak of already exists, it's the virtual radar display at the bottom of the screen. It even shows your trajectory so you can see if you will be entering that airspace soon.