I know this isn't the right place for this and I know that I will be criticized and I fully expect wumpus to come hurt me and stuff but man I really feel like you've got a few very serious usability problems that I don't know how you solve.
I personally find infinite scroll to be almost unbearable. I honestly participate less than I would like to because of it. Here's an example:
Let's say I have been gone for years (I have been) and I come back and I want to catch up with the last maybe 30-50 posts. In a paged forum all I have to do is go to the 3rd to last page. Here's what happens in Discourse:
1) I attempt to use the blue scrollie thing to go to the last post.
2) This does not work for me about half the time. I drag it down to the bottom and nothing happens.
3) I do this again to get to the end and it works the second time.
4) I start reading backwards and like the really bad terrain pop-in in old 3D games, the earlier posts suddenly pop in. On some devices the scroll-to-the-past seems broken and I completely lose my place.
So it's basically very very hard for me to catch up on older posts in a way that is trivially easy in a paged forum.
Long story short, for me pages are essentially a "solved" way of dealing with navigating through a lot of content. There's a reason that ancient writing technology moved from being written on long scrolls that had to be unrolled to the right spot to pages in a book.
I really get the impression that wumpus simply will not do things in a way that does not conform to the way he wants to do things. I think it's very cool that he's done so well with his projects and efforts on SO etc that he can do that...I have a ton of respect for the idea of him having a vision and just gunning for it, but in this particular case it just seems like tilting at the most ridiculous windmill.
I'd like to think that in a perfect world Discourse could be forum software the supported infinite scroll for people that like it and allowed paged reading for people who didn't but I have a feeling wumpus will tell me that the design is so tightly coupled to the infinite scroll paradigm that it's "impossible" which is to say prohibitive in the extreme.
Anyway, I don't really know the history of whatever wars went on over infinite scroll and the conversion to Discourse so I'm sure I'm just repeating something that was said before and probably declared anathema, but I kind of just had to vent and say that I really think that it's a very bad design choice for forum software.
I'm perfectly happy with infinite scroll in some other contexts (like when LinkedIn is showing me an ever expanding list of people I might know) but for a forum it feels utterly wrong.
But cheers and best wishes wumpus and I hope you succeed and that the group of people that enjoy this paradigm make this another great success for you. For me I'll kind of have to use it somewhat begrudgingly. :) I admire your chops and visionaryness tons but this one design choice just isn't for me.