Have not tried any of the development versions, yet, so if this idea has been implemented, already, I apologize.
While using V 5.1.9, I have found myself, several times, unclear about whether or not I am still in Place Symbol mode or in Place Wire mode. This could be significantly improved by making the icons, themselves, modal. That is, while in Place Symbol mode, do something to the icon/button to indicate that it is operating in that mode. Maybe change the icon background color, or draw an outline around the icon or change the icon graphic. Outline might be preferable as you would not have to pay nearly as much attention to color themes.
And a big thanks to all the contributors and developers who are putting so much effort into KiCad!
Oregon Research Electronics