I'd really like to have a "Direct To" button in flight mode.

I haven't yet seen this proposal elsewhere, but it is IMHO related to the "nearest" function which is a straight consequence of a "Direct To". When tapping a Direct-To button, a list of the nearest airports/navigation-aids/locations should pop up, including the distances to them. Tapping one of these should then create a respective navigation to this point.

It is worth a discussion whether or not this should

• replace the current route, or
• insert this choice into the current route

maybe with a default setting of "insert" and an option to select "replace".