The Yogins sutra and Aizen-Myo-o

[bogert]

Hi everyone,
I did a translation of the Yogins Sutra a while back because I had heard about its uniqueness to Japanese Mikkyo. I have also heard and read about the possibility (likely) that it was actually written in China and not actually translated into Chinese by Vajrabodhi as the text itself states. That is most likely why it is now unique to Japan, with no translation of the text existing in the Tibetan tradition, although similar deities do exist.
For practitioners does this make any difference to you that it could be an apocryphal text? Aizen Myo-o and his sadhanas seem to be used quite often in Shingon-shu and Tendai.
What also peaked my interest was a few days ago I went to koya-san and visited the Reihokan museum. There I saw the painting of two-headed Aizen with Fudo Myo-o mixed together. So I wondered what textual backing this practice has?
It doesn't seem to be included in the Yogins Sutra, or mentioned in the commentary I translated. Of course it could be mentioned in some other text.
I also noticed a number of mandalas with Aizen as the central deity. These are also not seemigly mentioned in the Yogins Sutra.

So, again what I'm wondering is, for practitioners of Shingon Buddhism, does this make any difference for you to practice sadhana that were mosty likely made up in China or some in Japan?
or
These practices are beneficial to your practice because they were revealed to a Shingon priest at some point and are now a part of the tradition.
or
The do you think the text was actually translated by Vajrabodhi.

Also if anyone has further infromation about these practices that could be shared in a purely scholarly manner (I respect the tradition, so would not practice anything I was not given permission to practice.) that would be greatly appreciated.
Thanks for any insight
Chris