I see the point for some uses, but for car navigation this can be
extremely annoying, if one is operating in a mode where the driver is
really making decisions and running osmand to 1) show distance to turn
that one is wanting to take anyway and 2) be set up to start navigating
for real in the event of detour. This may seem odd, but it's what I
usually do when driving places where I know the roads (which is most of
my driving).
I found the 'you have been off the route for 300 meters' to come late,
and to make way too much noise.
So I could see an off-route alarm menu choice among
quiet (just give new directions)
brief (just say "off route" and then as quiet)
long (as it used to be)
alarm (alarm tones and then as long)
It's pretty clear this is a) a persoanl preferance and b) situational.