Are you talking about using 3D Touch to enable keyboard trackpad controls for the cursor?
If so, 3D Touch isn't working in the latest beta, as mentioned in release notes.
You can also do pretty much the same thing using Haptic Touch by long pressing on the spacebar to enable enable keyboard trackpad controls for the cursor.
I only experience problems in Safari (URL bar). When holding the space bar the cursor sometimes disappears and you have to do it again a second or third to to make it work.