Sardines
Hall of Fame
Not everyone. I've been swinging tennis racquets the same way for over 35 years. I'm not about to change now for ANY string. If I don't get the same results with a new string with by existing swing? I cut the string out. I don't EVER change my swing. I hit flat regardless of what string I'm using. I don't try to swing bigger for more spin just because I'm using poly. I'm sure lots of people are just like me.
BTW, you didn't mention how old you are and if you use a two-handed backhand? Both are very important factors in developing tennis elbow.
I think you've got answered yourself. To generate topspin you need to brush on the back of the ball. If you didn't attempt to hit topspin (by your own assertions), then no string or string pattern or racquet will generate topspin for you. So of course polys (or any other type of string isn't going to do anything). In fact, if you strung the poly at a high tension, being a stiffer string, you get more impact, it's physics.
I think you are also missing the point of what I'm trying to say regarding strokes. You may have a 35 year old stroke, but even then you adjust your swing to hit the ball for a certain result. Strings and racquet, court surface and other factors change the way you hit the ball, so there is no constant stroke that is even 90% the same ... possibly if you are player against the wall.
Physics dictates you change the racquet face angle, swing speed and length of stroke depending on the ball you want to hit, or whether you are 3 ft behind the baseline or in no man's land. All those variables change the type of force your arm takes. I think I can't be clearer than this.
Frankly I'm shocked at why you tried to use a poly anyhow if you don't want more spin controll? The premise of the poly is to allow better spin and great power at the same time.