I love ACC in my 2020 accord (which is the same generation as your 2019). I've never had it hit the brakes hard enough to be jolting, even when a car changes into my lane.
The LKAS is hit and miss, like you said, unless the lines are very clearly visible, it can't stay in the lane. I wish it looked at the car ahead to help with lanekeeping. But it's never surprising when it loses sight of the lane markers (though it does tend to drift to the right at exits, but it doesn't make a sharp move). But even in its current state, LKAS is great for long freeway drives.
The LKAS is hit and miss, like you said, unless the lines are very clearly visible, it can't stay in the lane. I wish it looked at the car ahead to help with lanekeeping. But it's never surprising when it loses sight of the lane markers (though it does tend to drift to the right at exits, but it doesn't make a sharp move). But even in its current state, LKAS is great for long freeway drives.