Well, I am happy to say that I took minne to my mechanic and he DID it correctly, it seems.
He went with the DexIII spec, which was fine with me.
Dropped the pan changed oil and filter... all very boiler plate but then...
He actually purchased the dipstick that you need...
and....
he found specs that said where on the dipstick the fluid should measure...
and... AT WHAT TEMPERATURE!

So he put in the fluid, ran the car and monitored the transmission fluid temerature.
He told me when it got hot, he took a little out.

He showed me the ALLDATA graph - a piece of paper with a graph on it - which spoke to where the level should be depending on temperature.

So it is not not like the factory where they pour it in knowing from the git they are using the correct amount.

Sadly the trans does not drain completely (at all) cuz of torque converter retaining a couple quarts, so, measuring the level at different temperatures is the most accurate way to know.

And... the purpose of doing the flush once and only one per lifetime of car is that they figger there may be some particulates that gather in pan from new machinery wearing in and, get rid of those once, then use the finest synthetic available.

btw: Interesting fact.... did you know that as late as the 1960's American (and other) auto transmissions used WHALE OIL in the transmission? My oh my we have come a long way. (Think solar energy... in its 1940's and what cars were like then and 80 years later. Solar is kind of clunky now but give it a few years...!)