Thanks all for the suggestions.
I had a single intrusion box before and it didn't work well. I tried it again and now I know why it didn't work. Once it lose track of a subject in a large box, it stops to look for any subject again even though the subject reappears in its FOV. With multiple rules and boxes, at least the cam has another chance to get triggered when the subject enters anther intrusion box. At least that is what I am guessing.
Lowering Tracking Target Size improves tracking a bit, especially when the subject is close to the camera and the camera can't zoom out any more. A wider lens could work better here, but would lose the zoom distance.
As for picture quality, We don't get too many sunny days here in the Pacific Northwest. The picture quality is actually pretty good on cloudy/rainy days
. I did lower the exposure just now to minimize blown out areas caused by the dark shadow.
The latest setting I have is Target Size at 25, max size 8191x8191, min size 0x0, 3 intrusion rules and a tripwire rule, and moved preset 1 up to include more space so more of the subject can enter the cam's FOV to get recognized before it trips the wire. Will test it out.