I just checked in 2 more related things in this department.
Some people are just not into all this like stuff, they just want to interact based on content. On BBS someone described the likes notification as “background radiation”, some people are into it, some not.
This is not a unique problem to Discourse, for example a bunch of people on facebook complain about this as well: Facebook
On one hand, like notifications, “increase the social”, provide a “poor man’s” presence feature and so on. On the other extreme it can be simply perceived as noise. Users should be allowed to pick which end of the spectrum they are on.
So now we also have a “Never” option to complement the “Always” option.
Also, while debugging all this code I discovered there were no limits on “like/unlike/like/unlike” sequences. I added one in. There is a one minute rate limit for like/unlike sequences 4 transitions allowed per minute