I remember thinking about this exact problem (branching conversations, in particular audio), but I couldn't find a reasonable consumption pattern.
Looking at how I consume podcasts, it's a completely passive experience - I probably have something in my hands and can't talk. Choosing paths is just too much interactivity.
I figured that maybe that's just a wrong mode to look at it and people can consume the whole thing differently, not as a podcast. Ok then, I'm an obsessed power user/fan, I consume the whole thing, all branches. Given how human attention/memory works, that means returning to earlier parts of recording after listening to branch at least some of the time, multiple times experiencing 'where did we start? Let me go back a bit. Oh, that topic was the starting. Let me forward a bit now that I know it'. That's horrible, I think. You were at least more reasonable than me when thinking about it and decided to have only 1 level of branching ; )
In similar vein, what happens when comment gets added after I already listened/how do I know which parts are 'the definite experience'? Unlike previous two issues, those questions are answerable, but I'd still like to hear what you think the answers are!