I finally went the Techstream route, and changed the most apparent setting for Chime disabling under "Customize Setting" -> Warning for front passenger seat-belt.

To my dismay, it only disabled the chime that occurs when actually driving without the seatbelt, when what I was (only) looking to disable - and Techstream did not disable - was the highly irritating "ding" that happens if I get in the car, turn Power On to get into Ready Mode, without even putting the car in Drive. That chime is a mindless act of stupidity to even be there and is highly irritating - because every time I get in the car and put it in Ready mode, I don't necessarily intend to put the car in Drive, at least not immediately. So I was actually hoping to kill that "pre-driving ding".

Can others who have used Techstream confirm if they were able to disable the "pre-driving" "ding", and if so, how with Techstream ? Those who used Carista, did that route disable that "pre-driving ding" ?

 

You cannot disable the "pre-driving ding", at least with the Carista app anyway. Techstream is probably similar. The only way to stop it from sounding is to connect your seat belt before starting the car.

 

There are plenty of those belt buckles out there that you can buy and insert into the mechanism in the first place, then when you are ready to drive you disconnect your empty buckle and connect your seat belt buckle

 

Yes, I looked at the "pass-through" buckles (that call themselves "extenders") that won't need any detachment when wearing the real seatbelt. However, I couldn't get the confidence that those "extenders" won't malfunction and flake out, negating the safety of the seatbelt in the event of an actual accident. So I guess I will have to live with the idiotic pre-driving "dings". I will probably go ahead and enable the while-driving-dings, since that is the true safety feature - I don't actually believe those are the problem for me at all.

If anyone found that Carista somehow disables the "pre-driving" dings, please let me know - will have to use Carista instead.