@lake in regards to the last one: yeah its a hyper niche spot to be in LOL, though the tag kinda reads pretty broadly for the whole web and not just the fedi [though maybe that doesn't have to matter that much?]
#feditattooer ? #feditattooist? Though that sounds more like something for a person who started pursuing this back on the 90's lol
Functionality #FediTattooArtist , while a little verbose, might be the best fit. If not that than #FediTattoo