I think they should have it so there's a type of "slow down" light that supplements the brake light for when your deceleration is from taking your foot off the gas.
A few times I've had to use my alarm when other people are sleeping and it usually wakes me up (because I'm used to it) without waking anyone else up too.
Here's the technology connections test/analysis from 2023. https://www.youtube.com/watch?v=U0YW7x9U5TQ
The claim is we need more comprehensive regulation for brake/slow down lights.