Suggested

Vibration as an option

Could the starting race countdown vibrations be an option?

Lights are nice but on mobile, there is also vibrations and it is not always wanted.

If one wants some discretion it is impossible.
You can't play at a movie or during a meeting...

Turn vibration off on your phone i did it

I did not thought about turning off phone vibrations...
But it's a bit cumbersome to have to turn it off and on after the race.

Edit: I tried that today, using the "do not disturb" mode from my phone, still had the vibrations.