Hi Bewell,
Yes there is no question that Yogani's images is anatomically correct,
but if you found the erectile tissues, then you know that the tip of the tongue
is clearly closer to the nostrils than it is to the uvula.
So the kechari stage 2 is not depicting the tongue entering anywhere, it's just touching
the "door". That's why i did those drawings, but in the end the tongue clearly points upwards
and not "forwards" as my drawing.
As for the stage 3 i still find something strange in it, because the tongue has to first "enter"
a cavity, and then proceed further up, but Yogani's image is not depicting the tongue to enter
anywhere.
I think i would a very good idea to follow Shailendra Sharma's, experience, and get ourselves
to perform the Kechari Mudra, while scanning our heads with MRI, then we could finally decide this
thing out!
Blessings