Consider one emergent discussion as a collective knitting job. Each monk can view it, appraise it, expand it. Or consider it a symphony of voices (Tolkien style?) In any case, some locus or front is implicit, with the work inexorably progressing along the time dimension, toward resolution. A piece that keeps morphing while you look at it, is probably not the easiest to work on. I see the new default order, and I'm not liking it.
Proposal: if the tree must sort by the girth of the branches, then perhaps a hybrid rep/age based view might be more manageable. Recent topics are works in progress and better viewed chronologically, IMO. Leaking the reputation is not good either, and can bias the voting. So, what if the algorithm was to pick a hysteresis threshold that is large initially but decreases along the optimal two-week voting period? A stable sort to rearrange the descendants where the reputation diff is above threshold.
But really, I think the key concept here ought to be careful pruning of information: it's not so much about the sort order but presentation. A good overview will be compact enough that the important bits do not disappear; the bits can be highlighted with the order preserved. (Also, the end of the thread is probably more visible than the middle. Do we really want to lump the noise at the end?)
Further. There was a polemic regarding some unhelpful content; opinions were put forth of suppressing said voices. Well, that would appear to be concentrating on the negative. (One wouldn't want to keep looking at potholes when riding.) But a gentler approach could be adopted, one to ensure that the good content is properly featured. Tree view is depth limited—what if this limit was adaptive? Some condition (user option) to count certain nodes as zero-depth ie never pruned if the parent is shown. A +rep node following -rep; or a +rep node following lesser rep node.
Rationale: do not cut off discussion where it probably shouldn't; good retorts or important corrections must show up.
Another thought, but this is less relevant. I have a certain distaste for trivial, back-and-forth, A-B-A-B-A-B kind of exchanges. Suppose those deep, unbranching strings of messages were flattened to one indent level (count fractionally towards depth?)