rtmozingo
FRF Addict
You're correct it will apply the brakes even if ACC isn't on, I know because that's exactly what mine did. Not only did the alert go off but my incident would've been an imminent crash, however, the brakes were also heavily applied prior to me stepping on the brakes and it saved me from a crash.
I own a 2019 802A with Technology package.
My 2017 does as well, and someone else with a 17 has a video on youtube showing it.
The manual for the 2017-18 says it only primes the brakes, but at least a few of us have trucks that will auto brake without the ACC on.