To expand on this, all that we really have is a feeling of self-awareness, and a memory of a continuous series of events leading up to this moment. Both teleporter clones would have the same subjective-I feeling, and the memories. Which one is “real” is a meaningless distinction.

I disagree, at least if we're talking star trek transporter. For the person who stepped into the transporter, their conscious experience ends forever. The person who steps out the other side has the illusion of continuity and will understandably believe themselves to be the same person, but it won't be the same person. As I see it, the original person's life experience ended permanently when they were "destroyed" by the transporter. The fact that the copy will perceive itself to be the original doesn't change this.

In some hypothetical where you are magically moved without being destroyed, I could accept that the same person who teleports from spot A is the same person who arrives at spot B, but so far I have heard of no technological idea of teleportation that convinces me people aren't dying every time they teleport. (I know we're just debating fiction so it's arguably meaningless, but I'd for sure be the guy in Star Trek who refused to use the transporter.)

The legal issues of having two selves are interesting, but seperate from the moral ones. Legally, I dunno, it depends on the teleporter malfunction laws in my local area. Maybe the teleportation manufacturer becomes liable for duplicating my quality of life for one of us, like a weird technology third version of alimony/child support.

Morally/emotionally whatevet you wanna call it, both of me would be married, as everyone present (me, myself, and my wife) participated in the wedding ceremony. My wife's vows apply to the both of us, and each of us took vows to my wife. My child gets two dads, since we both fathered her, and she gets to deal with three parents.

I imagine we'd both just live together, and share ownership. In my jurisdiction (the real world, fairly local I'd say) there are no laws about this, and I suppose we'd share our SS number and identity, if for no other reason than neither of us wants to go to court to try to change it. I think I'd choose to switch my first and middle name, so we could differentiate, but still be us. It'd be neat.

These are legal and cultural questions with no objective answer outside that context, so its simply up to those involved to figure out what they prefer

Easy solution: put all those things through the teleporter/duplicator

Would that even be the OG Riker in your scenario? He'd have almost certainly have used the transporter many times before then.