I'm pretty sure that's a different project

Its the only repo by the author(Edward Chalk) that focuses on decision making models? Its his github account linked from the front page.

I'm pretty sure it's a different project. It's not that inconceivable that the same author has done more than one project in a related area, especially if the one you found on github is obviously different to the one described here.

There aren't very much of alternative to Reddit at that "Top100 websites by traffic" scale.

No alternatives in finding communities with your specific interests either.

The solution is allowing the convenient web interface only for trusted members, like e.g. 4 year old account can view all pages(with easy anubis setting) but guest/bots/everyone else has to git clone the thing and do it on their backend. IIRC old forums also limited 'content for registered/trusted/moderators/etc' content views decades ago, turns out this crap saves gigatons of traffic.

That excludes new legitimate users, just put up a very cheap paywall for the web interface, 1 dollar for lifetime access, that way each request is tied to a user and can be rate limited. While remaining essentially free.