I searched around some more and now I actually think cervical penetration is possible. There is some fetish kink out there where they do it with a speculum and additional gyno instruments. The women even seemed to be enjoying it, at least with 1-2 cm dilation. It would take training on the woman’s part to gradually stretch the cervix to allow for greater sizes. Probably a lot of training over a long period of time, and probably not entirely healthy or safe for her.
Also saw some scattered anecdotes of men and women who had been to the doctor because of sex problems, and their Doc told them there was cervical penetration going on.
So reach for the stars swaffel!
Before 5.5" x 4.1" ///////// Now 7.4" x 4.9"