I think the key here is to keep the "edit" toolbar active.
Since it also allows not only view the mode but also easily switch between modes.
Unless want edit midi only with the keyboard... but I find the mouse infinitely easier.
PS
"The icon should reflect the shape of the tool when the mode is selected."
It would certainly be helpful, even if it is indicated on the toolbar, you have to look away.
If the cursor always indicated the mode, editing would be more reliable and intuitive.
(as it happens in graphic editing software)
I think the key here is to keep the "edit" toolbar active.
Since it also allows not only view the mode but also easily switch between modes.
Unless want edit midi only with the keyboard... but I find the mouse infinitely easier.
PS
"The icon should reflect the shape of the tool when the mode is selected."
It would certainly be helpful, even if it is indicated on the toolbar, you have to look away.
If the cursor always indicated the mode, editing would be more reliable and intuitive.
(as it happens in graphic editing software)