I do know the polling industry from Honors College political Science classes covering their use to control the populations. Such polls are not unique to America, Every tyrannical government of modern times has used them.
There are 2 types. One is private and used to measure. The Public ones do not measure anything, their purpose is to manipulate. They will put out some that look legit to get people paying attention to them but they earn their money when they shape public perception. Their business model is based on how effective they are at delivering the results their clients want.
You are close. The ones I refer to are the private ones you speak of. I have not seen them but have some knowledge from within. No specifics but some useful information.
I believe the information from whom I got it much moreso than public polls.