After disabling the
terrible sound and riding without it for 2 months, I can say: a big relief....
Yes, it has one major drawback - completely disabled internal Navigation and a problem with
Android Auto (but there have been problems with it before and there will probably always be some). But it's worth it. I can't imagine driving it again.
Apparently I finally figured out the trick (this is not a “hack”) to permanently turn off the sound notification (it can be reverted). It's easy, it's done in 1 minute. If anyone is interested, send me a private message here and I’ll give you the instructions (I don’t want anything for it).