Yeah I have to agree. My insurance agent warns against waving people on or even pedestrians. It’s dangerous and transfers liability. Just follow the rules and don’t try to be the nice guy. Kills me at a four way stop, someone franticly waving me on when it’s their turn. Either they are afraid or are trying to take control.
I also have to agree. Back in 1967, I was a social work intern for the state’s child protective agency. My assignment one day was to pick-up one of our abused kids who had been getting psych therapy at the county’s mental hospital.
He and I were in the process of leaving that facility, and the view of oncoming traffic on the adjoining road was extremely restricted. A 20-ish guy was standing adjacent to the exit, and he waved me on, saying… it’s all clear… or something to that effect. Yeah, you guessed it… We almost got creamed by a large truck, and the “helpful” 20-ish guy was convulsed with laughter.
I mentioned this to my supervisor when I got back to the office, and she informed me that some of the mental hospital’s patients were given the freedom to roam the grounds. Apparently, the homicidally helpful guy was one of those patients. Live and learn…
I know of 2 people who had accidents by being waived to turn left . Fortunatly no one was injured but my friends really nice vehicle was totaled.
I was trying to turn left out of a daycare one morning on a busy 5 lane road ( two lanes for traffic in each direction plus middle turn lane) and both lanes had stopped for a traffic light down the road, and the vehicles had given me enough room to pull out, the car in the left lane was in a undercover car (LEO, I knew the car) and motioned me to pull out, not being able to see, I pulled out and as soon as the nose of my car crossed into the turn lane I was hit by a speeding driver in the turn lane trying to beat the traffic light, well to say the least I was not happy and voiced my opinion to the cop for telling me it was safe to pull out and the other driver was in the turn lane much to early and speeding, I was then told that I was in the wrong and to drop it or he would wright me a ticket for not being in control of my vehicle at all times (something like that), since he was the Police Captain I decided it better to walk off… 
Same car, my wife was driving it and another city had the same thing (minus the LEO) happen to her, except this time she was much closer to the red light, the driver in the left lane motioned her to pull out and bam, the driver in the turn lane was going fast enough to push the front end over about 6" or more and deployed the 2 airbags, totaled my 3yo car (I still miss that car 
) plus the other car involved, yup you guessed it, in both cases my insurance (and me for the next 3 years lol) had the privilege of paying for all the vehicles involved…
To say the least, that was back in 1996 and 1997 and I will not pull out across 2 lanes into the turn lane with out stopping and looking VERY hard to make sure no one is coming, but most of the time I just turn right and circle back around down the road or turn right and drive to a red light to get turned back around…
Yeah if someone waves you out then go and stop in front of their car to make sure that the second lane is clear. If you end up stopped in front of them for a long time they might rethink waving at cars to tell them to pull out.