Monkutare , great handle by the way, to your first question , its up to you but normally if you are hitting #1 is direct drive, if you are swinging #1 is not being thrust against. Either way swinging or hitting , normally the #3 is not being thrust against but only senses the inertia. Its on the aft of the shaft like the seat against your back in the car. Inertia as opposed to a point which is thrust against. This Lag Pressure dissipates as acceleration slows or when the clubhead passes the hands making it very useful for monitoring thrust and also directing thrust when you Trace the delivery path of the clubhead through the ball with it.

With training the #3pp becomes an indispensable tool. To sustain the amount of pressure sensed is to maintain a rate of acceleration. Force = Mass X Acceleration. To direct it is to trace your desired clubhead path through the ball. Physics and geometry. Clubhead force and the path of the clubhead.

Lag Pressure ........Pressure......it isnt left hand wrist cock in a common golf speak sense. Nope.

Thursting against #3pp , can induce throwaway.......so it'll feel like lag pressure but it isnt. Its pressure yes but not due to inertia alone. That'd be the flippers direct drive of the #3pp. Its a false feel. Try maintaining the right wrist bend and sense the inertia at the #3 with just your right hand on the club for little chips and see if you can feel it. If you're like me you'll notice a correspondence between purely compressed , sweet contact and lag pressure maintenance. If you feel like you have maintained the amount of lag pressure through the ball but the shot is crap suspect throwaway, the false feel of direct drive at the #3pp. The right hand frozen in a bent position (appropriate amount of bend for the ball position at hand) will help with the throwaway. The right wrist does not straighten through the ball, it is not a source of power ideally , as it is often accompanied by a bending of the left wrist.

Sustain the Lag.
O.B.

I can feel PP#2 and PP#4 on the downswing. Is it essential that I can sense PP#3 and PP#1 on the downswing?

Also, why is it that when "dragging the wet mop", you cannot use the right hand to pull, since your right hand is in front of the clubhead/mop head?

#2 and #4 pp on the downswing is really great, ideal even for a Drag Loader, be he a Swinger or a Hitter with a Swingers Startdown (Four Barrel). A swinger would not typically have a strong sense at the #1 cause he isnt thrusting against it like a Hitter or Four Barrel guy. #3 is inertia something that is there unless you arent accelerating at the same rate which itself is essential to good power golf, full swings. But the perception of the #3 pp, the ability to read it to employ it as a tool is a learned skill. Indeed I believe pp#3 awareness becomes golf "concentration".

For sure there are champions with no concept for lag pressure at the #3pp, but that pressure must exist in their hands though they dont recognize it intellectually. The oh so common "trigger finger" of the great golfer suggests that to me, though its an assumption on my part I admit. There is lag pressure elsewhere in the grip too of course not just at the #3, but given a common grip type thats where its focused. I would say that any good golfer has a feel in his hands he employs but is #3pp (awareness) a requisite to good golf?.........No. But the presence of lag pressure, inertia is. So why not find a method of sensing it, meetering it, directing it through the ball. Hence the lag pressure point , #3pp.

Speaking of "directing" the #3pp, the #3 attaches to defines the top of the Longitudinal Center of Gravity, the Sweetspot defining the other end. So to direct the #3 is to direct the sweetspot specifically , literally. So #3 awareness can be restated to "sweetspot awareness". Putting your brain in your hands is really also putting it in the sweetspot.

You can drag the wet mop with a leading right hand/arm........that would be the Right Arm Swingers version of the analogy. The Drive Loader, would be Drive the wet mop. The Drag Loaders would be Drag the wet mop. The Four Barrel guys would be drag then drive the wet mop.

OBL
Thanks for taking the time to answer my questions. I have been trying to work through the basics, but it is frustrating.