Thanks SteveK2016, for that info. To simplify for readers of this thread, I am going to extract the text of some successful stories of
Opting-Out of uberPOOL
Worked for many in Atlanta. Below are selected example text.
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I have another account question
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1st attempt
I keep receiving pool requests. I would no longer like to receive pool requests as it is unsafe and refusing those requests is affecting my income and acceptance rate. please take me off pool requests. thank you.
Uber's Canned Response
<standard opening BS>...There is not currently an option for partners to opt out of specific vehicle options like UberPool or UberX...<standard closing BS>
2nd attempt
I am sorry but that is not true. many drivers have gotten themselves taken off uber pool in <your city>. I want to be taken off as it is not safe for me, my passengers or my rating and acceptance rate.
Success!
<standard opening BS>...I've reconfigured your <vehicle description> to opt out of the uberPOOL. platform. You should no longer receive uberPOOL requests using this vehicle option moving forward. Kindly refresh the partner app on your device...<standard closing BS>
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My Pool is Closed! 4 tries.
1st attempt
This is a request to be removed from UberPool. Please remove UberPool from my profile completely. As an independent contractor I will not accept UberPool requests. It is also to note that UberPool is a serious hazard for both drivers AND passengers.
As a driver, being redirected in route is very distracting, and that alone is enough reason to not pickup pool rides. It is also really an issue that drivers can only choose if they are picking up 1 person or 2 people. I can not count how many time I have picked up 2 people at the first stop and 3 more were waiting at the second pickup. Then, drivers have to rate the first drop off while the 2nd is still in the vehicle, while they can easily see what you rate that first passenger. As a driver I have been forced into many uncomfortable situations having to mediate between passengers, this is absolutely unacceptable. My ratings have taken many hits from passengers being upset by dealing with another passenger, absolutely not acceptable. Finally, my acceptance rate takes a serious hit if I don't pickup Pool rides, and if I pickup a pool ride and then choose go offline I take a MAJOR acceptance rate hitting because the app doesn't send the new requests to me at all yet still ignores them.
Passenger hazards are as follows. On several occasions I have picked up a female passenger followed by intoxicated males. Multiple times the female was sexually harassed by these passengers. This is incredibly serious and absolutely not a joke. In one case the men were getting dropped off second and the female was so scared she had me stop at a public gas station to avoid letting the men know where she lived! On another occasion a Bartender had me do the same thing as he felt unsafe with the other passengers knowing where he lived due to carrying cash on him.
These are but a few of MANY reasons I wish to have UberPool removed from my account. As an independent contractor I will have no part of UberPool now or in the future as it is absolutely an unsafe, unprofitable venture.
Thank you for your time.
Similar Uber responses and 2nd to 4th attempt not copied, but resulted in Success!

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The moral is DO NOT GIVE UP, KEEP TRYING. Expect minor variations in different cities.
Please reply with your success stories.
Finally, similar requests have been successful in Opting-out of UberX and UberXL for those with higher classifications of vehicle (like uberSELECT). For examples, go to
https://uberpeople.net/threads/opt-out-uber-pool.112556/