I do not know the answer to your question, but suspect 8 may be indeed
correct.  Power flushing is something that makes the dealers a lot of money
with less labor since they use MORE fluid to assure they get the majority
out.  Power flushing also does not get the debris trapped on the bottom of
the pan and in the old clogged filter.  You really need to drop and fully
clean the pan and replace that filter.  The drawback is that this will not
get all the fluid, but if you really feel that is needed, then do the power
flush immediately afterward and you've done it all.  Lastly, make sure
whoever does this work uses only the specified fluid since these
transmissions can be temperamental.  Many trans places use on GM Dexron and
add an additive and tell you that this is the same as DSM, Chrysler, etc.
BUT be forewarned that this is definitely not true and can lead to major and
very expensive transmission problems.

Good luck

       Bob