Some stuff to play around with and experiment.
Grip pressures are actually opposite....here is an experiment for you....Take your first finger and thumb and press them together firmly....keeping that firm pressure attempt to move your wrist....You will notice that your wrist will be very stiff....In fact..you must relax your first finger and thumb pressure to move your wrist....
Now make a fist with just your last three fingers (keeping your first finger and thumb relaxed)....notice you even though you have firm pressure on the last three fingers (as long as your first finger and thumb are relaxed) you can still move your wrist more freely.
Golf grip is the exact same as above....the club is gripped in the last three fingers...The first finger and thumb are basically just along for the ride....Someone that grips the club wrong...I can yank the club right out of their hand....Gripped correctly in the last three fingers is a much more stable grip....(with more natural wrist action)
Here is another (observation).....make a line down the middle of the back of your forearm down the middle of the back of your hand.....That line will go directly to your middle knuckle on the back of your hand.....(it does not "jag" forward to the first finger knuckle) ......Too me that tells me I want that middle finger to kind of act as the "fulcrum" point of the stroke....(not the first finger)
For me....The first finger and thumb are on very lightly....My pinky acts as a rudder (and restrictor) so to speak....My personal stroke issue quite often is taking too much of a backswing....keeping the ball of my pinky finger directly under but touching the cue helps keep the cue stroke straight and also helps restrict the amount of backstroke I take...same thing for the ball of the first finger....keeping the ball of the first finger directly under but lightly touching the cue through the stroke helps keep the stroke straight.
This part may read a bit goofy.....In Golf....(putting) your putter's shaft acts as your wrist (flex).....So your actual wrist remains pretty much "hinged" through the putting stroke....(many different variations to that hinging)....In pool...since we kind of flip the stroke on its side....your forearm/wrist become the (putter) shaft....so there must be a bit of "flex" (kind of like a putter shaft).....Now if we exaggerate things and say our shaft was a rubber hose...it would be very hard to have any control or consistency.....If the shaft is too stiff like a brick we would loose all feel....what we want is that happy medium were their is a little flex in the shaft but not too much or too little.
Ideally you want that wrist "flex" to happen naturally without any thought....Forced wrist flex is very hard to repeat over and over....natural wrist flex (since it happens naturally) is much more repeatable.....
Now....what can we actually "control" in this situation.....We can control the way we grip the cue and where and how much grip pressure we can apply.....everything else wrist flex, stroke path, etc. is a "result" of the static part (set up) that we can control.
Ultimately...If the cue is accelerating along the correct path through the CB...success....It really does not matter how you get it there......It just has to get there,
Sometimes (to me) when I am in that groove that occasionally I fall into...That I am always striving to reproduce on a consistent level.......It almost feels like my backswing is like I am simply drawing back the rubber band on a sling shot and then I release the rubber band and my grip hand/cue just "wants" to go forward without any effort input or force from me.....Its about as close to the "Ya just know" zone I can get that Eddy talks about at 1:30 of this clip.