Another Sun Orchid variant

Clearly this is a form of Thelymitra ixioides - the "Spotted Sun Orchid", or a hybrid derived therefrom.
Here is a close-up of the column of this (or a similar) flower.
To refresh your memory, this is the standard form of Thel. ixioides as found in the NSW Southern Highlands.
The "column arms" are right, but there is a difference (in the previous flower) in the "post anther lobe" the ring of tissue at the top of the column. This one is tipped yellow. The other is brownish-red and much more warty ("pappilose").
My Victorian colleagues publish images of Thel. ixioides with dark rims to the "post anther lobe". Here is a link to JL's images from Great Western (in the Grampians). Her photos match Colin Rowan's (taken at Anglesea).

In the same area, at Penrose, there were many of these lovely unspotted forms of the same plant.

I say that with some confidence, as this species is renowned for its variant forms, including an unspotted form of the "Spotted Sun Orchid". Confused? Don't worry - so am I.

Here is a closer image of one of the flowers.
It was a lovely blue specimen (without spots).
And here is probably my best image of the column
and the column arms.
So, what have I got here?
It might be the hybrid form of Thel. ixioides,
which is known as "Thel. x truncata".
That hybrid form has been named,
but the photos of that hybrid which I can find
do not seem to me to be truly diagnostic of the hybrid form.

Or, should I say, if their photos (from NSW and Victoria)
are true hybrid forms of "Thel. x truncata",
then these plants (in my photos from Penrose)
are of something else entirely.

Fine.
But what?

Any advice would be appreciated.