We are noticing that many of our users don’t figure out by themselves how to use the progress bar at first, in particular, how it enables to jump directly to the top/bottom. I think it isn’t immediately obvious to many that the dates are clickable until one actually uses them.
One idea would be to include a step of the discobot tutorial to get people up to speed on the progress bar (eg: go to top/bottom & time travel). Another alternative would be prefix ↑ and ↓ to the dates themselves, but I reckon it’s perhaps not the most pretty thing to have.
Until a user figures that out (by asking, by reading a user guide or just by trial&error) getting to the bottom of a very long topic can be a frustrating experience for a new user. Perhaps this is something that could be introduced as part of the tutorial?