I don't think you would want to actively "drive" #1 after 4, 2, and 3 have been released. The resistance to deceleration is set up with Extensor Action pressure and remains constant throughout the stroke. As the accumulators release and momentum is transferred toward the clubhead, the heaviness and hand slow down is resisted by Active Extensor Action. It feels like pushing and in some sense, it literally is pushing in order to keep the hand speed constant. In that sense, it's a 4,1,2,3 release sequence with all accumulators still active at impact, but you are still dragging the clubhead.

An analogy might be a wet mop that is going to go through a sticky spot on the floor. You resist the deceleration with the heel of the right hand against the handle.

Most of the accumulators are not spent until after impact anyway, even though they release prior to impact. They stay inline and active into followthrough and beyond. PP1 continues driving to both arms straight, PP2 moves from level to uncocked, PP3 moves continues to roll horizontal to the plane, and pp#4 continues pulling with pivot motion.

The point I was trying to make is that the hands and clubhead decelerate as the accumulators release and the clubhead/ball collide. The 5th edtion of 2-K has some good detail that was lost in the newer editions. If you believe that the hands keep a constant speed on the endless belt for swinging, the best way to make sure this happens is to resist the slowing down of the hands as the accumulators release. PP#1 is all you have to resist decleration and as Homer said, it can add distance for the swinger...

But that implies you know how much pressure to apply before to the moment of truth. For most of us mortal golfers, all of this isn't necessary but it can be helpful at the TOUR level. The problem is that it is so close to turning into a HIT through impact, that it isn't worth it unless you really have it grooved.

Yoda or our other experts can step in anytime now as I've just about hit the knowlege limit on the 4B swing, pull/push discussion. :)

Did Hogan get it wrong when he said “On a full shot you want to hit the ball as hard as you can with your right hand. But this is only half the story. HIT
THE BALL AS HARD AS YOU CAN WITH BOTH HANDS. The left is a power hand, too. If you hit hard with only the right and let the left go to sleep, you will not only lose much valuable power, you also will run into all the errors that result when the right hand overpowers the left.
YOU MUST HIT AS HARD WITH THE LEFT AS WITH THE RIGHT.”?

I believe it is extensor action -as opposed to a out and out drive of the right arm,as per hitting.
I would best describe my right arm as "aware" rather than "active".
As someone who had a real problem being over aggressive and using quite a lot of 'hit' in my swing,i have done a lot of work on trying too eliminate the right arm ,other than RFT and extensor action and focus on snap release and finish swivel.And of course PP#3

After further review...
 

Strav, when I wrote:

It can't be done successfully or to any advantage. I did not mean to imply it can't be done (impossible).

So should Kebeal’s answer to the person who asked him is it possible to pull and push the club through impact at the same time be ‘yes - but it is not advisable’?

IMO, Keerect!