At the end, what's important, is the contact point of your tips on the CB.
So when people talk about a tip of english, what they really are referring to is a specific distance from the Center CB. Regardless of your tip shape/size, you need to hit that specific point to apply a given quantity of english.
I never use my center tip as an aiming point (unless I want to apply no english). I kind of imagine, depending on how much english I want, what part of my tip will contact CB, and I focus on that, as oppose as to where my whole tip is.
In the simple form, that's it, but the location on the ball is not the whole story.
For a flat tip ] Is the edge making contact?
or for a flat tip with just a radius edge. } ...
or for a radius tip with a nickle radius )...
or for a more 'pointed' tip like a dime radius > ...
at what angle is the tip surface when it strikes the ball even at the exact same location?
And would one rather have a soft, medium, or hard tip for any particular given shaped tip?
And for how long does the tip maintain that precise shape or radius & does a particular hardness of tip better conform to the radius shape of the cue ball?
How can one answer all of the questions regarding all that for another individual to choose what they might want.
It's experiment & feel based when it comes to one using an off center hit for an intended purpose, whether it be for the use of squirt or for the use of the spin.
I think we can all agree that a flat tip would certainly seem to be better for one that is trying to hit the center axis of the ball & will have some margin for error in that endeavor with that shape tip, but what about when one goes too far off center?
An athlete like a good hitter in baseball can grab one of two bats that weigh the exact same in total weight & tell if one is more barrel heavy than they like over the other one. Raymond Floyd & golfers like him can tell if the grip installer put on one(1) layer of too much tape. How thick is a single piece of tape? John Havlichek(spelling?) can tell that the goal is 1/2 inch too low or too high just from shooting a few shots on it.
Some are feel players like athletes & others are more mechanical players in the vein of 'book worms'. Some can feel small differences & others can not. I'm NOT talking about on one shot but on a series of shots like in the course of a game or two.
Each individual should make their own determinations & NOT rely on others. That way they will be responsible for their own game & not possibly find out way down the road that someone was wrong about something & they have been working under a misconception for how ever long.
Again just food for thought.
Best Wishes to You & All.