I was thinking already about implementation and already not sure that such behavior is right.
The selection could not be converted one two one without loss (block selection can be done outside of the line boundaries). And if selection will be changed without explicit user request, this will be not nice. Because such change can not be undone.
Even in Stream Mode you can do column selection, if Alt is pressed during selection. So, the status indicator is not correspond to current selection but to selection mode which is applied to new selection, if it done without modificator keys.
So, I will postponed implementation till further requests or comments from some other user here.
Let us see what other think.