Hi folks.
I have an answer to if a seeded plant can herm. The answer is yes!
Take a look at my bushy phenotype Durban in the first 3 pictures of this link:
Not noticeable in the first shot. Look really close at the second shot, about an inch from the top of the plant a “banana” (pollen sack) is visible. The 3rd shot is a closeup of a bud from the plant that had a banana. This plant had 4 seeded branches.
Fortunately, the plant was so far along its flowering cycle that there could only be tiny, immature seeds if any.