Good observation with the SSC natural experiment!
I actually believe LW2.0 is doing a pretty good job, and is likely better than reddit.
Just there is a lot of dilemmas implicitly answered in some way, e.g.
total utilitarian or average? total
decay with time or not? no decay
everything adds to one number? yes
show it or hide it? show it
This likely has some positive effects, and some negative ones. I will not go into speculation about what they are. Just if EAF2.0 is going this direction, I’d prefer the karma system to be sufficiently different from LW. E.g going average utilitarian and not displaying the karma would be different enough (just as an example!)
Also the academic literature on “social influence bias” (paper by Lev Muchnik, Sinan Aral and Sean J. Taylor from 2014 and followups) may be worth attention
Yeah maybe they could just select whatever karma tweaks would require the minimum code changes while still being relatively sane. Or ask the LW2.0 team what their second choice karma implementation would look like and use it for the EA forum.