I have a few thoughts and ideas about the Jem'Hadar I would like to share. Please share your opinions and your responses to my ideas.
Lamat'Ukan was part of the strike team that captured the Defiant in "One Little Ship". He later became the leader of the Alphas. Did his fellow Alphas (Sixth)Duran'adar and (Fifth)Umat'Adan survive? If they did, what happened to them since? I could see one of them taking up leadership of the surviving Alphas after Lamat'Ukan's death in "The New Link".
Kar'ukan's comments in "Boldly they Rode" about the Founders abandoning them seems to echo Lamat'Ukan's response to Odo. Is it possible that the remains of his rouge Jem'Hadar joined up with the remains of the Alpha Jem'Hadar? That could make for an interesting storyline.
Virak'kara was impressed by the longevity of the Trill in the DS9 episode "To the Death". Is he still around? It would be neat to see that he became a First and an Honored Elder. An option could be that he is the First that serves under Eraun in "Facility 4028" and "Boldly they Rode". While not significant, he could be added as a named ally NPC that follows the character in "Facility 4028", and as an interatable character on the bridge of Eraun's ship in "Boldy They Rode"
The Vorta, a far more intelligent species who handle a far wider variety of more involved tasks than the Jem'Hadar, are a series of clones who share the same lives, memories and experiences as their predecessors. We've never seen the cloning process that creates a new Vorta so what we know about it is limited.
We've seen the Jem'Hadar are incubated in vats. It would be very easy, in fact it would make the most sense, for the Jem'Hadar to be clones themselves.