Yes. The cut-in-half ballpoint pen spring on the top of the trigger takes out forward-back wobble and the nylon washers take out side-to-side wobble. Notice I said "wobble" rather than "slack". To me, slack means a "reversible" thing.. So with slack, you could pull the trigger back to take up the slack, but when you released the trigger it would return forward to it's original position. Wobble is useless movement per my definition. You pull the trigger back, and it stays back. You push it forward, and it stays forward. Useless movement - just an annoyance. That ballpoint spring I used gets rid of that useless movement.
With the 1377 trigger, at least with mine, there really is no slack. It is very hard to detect any discernible movement of the trigger when you fire. It feels solid. You start pulling it back, it still feels solid (you can't really detect that it's moving). Then it fires. You can see the trigger movement if you look while firing, but the travel is so small that you really can't feel it without looking. Me taking the wobble out with that extra spring doesn't change the basic operation of the trigger. With the normal wobble in place, you point the muzzle up and the trigger wobbles backwards. You point the muzzle down, the trigger wobbles forward. Finger pressure is not involved - the trigger wobbles on it's own. This is just unnecessary looseness.