I think there is a really valuable insight there in addressing how to build a new community. Rather than emoji use a key word net and at least initially 'cast a wide net '. You can always refine it later.

It did mean @nightwyrm.xyz had to spend a bunch of effort filtering out spammers and words we didn't want, like kiwifarms was picked up for a while. But it meant that people would accidentally post and that is powerful.

The "wide net" should be highly replicable for groups defined by unique languages and specialist terms (they should have an even easier time) The R user community has a very clearly established hashtag of #rstats which is almost the opposite case- a single way finding point people know to signal.