Haven’t had much need for it here.
On Reddit, I use it on those things that actively take away from the conversation. Trolling, pushing obviously wrong information, blatant racism/sexism/other-ism.
But, as little as I do use it, I find it supremely important to have. Trolls get downvoted out of the conversation. It’s a way to fight brigading. It’s the only easy/consistent way to give input as to what content doesn’t fit into a particular sub. Downvoting can be problematic, but it’s less problematic than those sites that try to be all warm/fuzzy and only allow positive input.
Ideally, if you create the communities and post questions, wouldn’t those that can answer then show up?
I wonder though if at this stage, it would be better to make a more general “What is this?” community, where you can post anything you’re hoping to have identified.