By "booster" comments we just mean comments that are highly positive but low on substance. "Great app!". "Congrats on the launch!". Comments like that are often an indication that a friendship network has been rallied to show public support and create "social proof". But often these kinds of commenters try to get clever and add in Dorothy Dixer questions about the tech stack or something else to make the comment seem more authentic and substantive, and enable more details to be shared.

Often when that happens, it's green (new) accounts or old/dormant accounts posting the comments and upvoting the thread, but there wasn't much of that here (though there was a little, which is what aroused suspicion).

But these comments don't have any effect on the thread's ranking. It's only a vibes effect.