If you press down harder while selecting text and drag you can select additional words without using the grab bars on each end of the selection.
Hmmm, maybe I was mistaken because now I can't get it to work. Weird! Sorry, false alarm.
It works. It takes a little practice.
Yup, it works but takes a little practice to be able to hit the right pressure points. Basically, you 3D Touch to activate the touch pad, ease up on the pressure just a bit (still keeping the touchpad enabled) and reapply more pressure to highly entire words.