People liked the idea of starting with some hobby instances and asked for some more possibilities. Briefly checked a bunch out to take some notes, and if any are of interest please check them out and reply with further observations so this can be edited and improved.

• pathfinder.social - mostly Pathfinder/Starfinder but also general tabletop, GMing, worldbuilding, looking for group and stuff
• mander.xyz - dedicated to nature and science [houseplants, mycology, reptiles, plant identification, astronomy, archaeology, biology, geoscience, geography, anthropology, physics, isopods, chemistry, underwater photography, & more] (has a really nice custom UI theme so federating would allow viewing hexbear with it)
• thegarden.land (alt) - gardening
• programming.dev - programming and development
• lemmy.studio - for musicians and music lovers
• waveform.social - digital music, reaper, flstudio, ableton, synths
• lemmy.film - for filmmakers, movie buffs, artists, creators
• lemmy.radio - for amateur radio enthusiasts to use
• fanaticus.social - community of sports fans to talk about sports
• sub.wetshaving.social - for discussions, reviews, and general sharing of thoughts about wet shaving
• pawb.social - sfw furry instance
• lemmy.sdf.org - SDF Public Access UNIX System, retro computing
• compuverse.uk - technology [computing, retro, self-hosting, game deals, tech support, programming, speedrunning, blu-ray, etc]
• social.fossware.space - for FOSS (Free and Open Source Software) Enthusiasts
• infosec.pub - information security
• terefere.eu - visual art, design, photography, architecture, artefacts, history
• lemmy.srv.eco - self-sufficiency, mutual aid, collapse, environment
• r-sauna.fi - all things sauna, in English but there's Finnish culture
• preserve.games - sponsored by hitsave.org [Hit Save! is a registered 501©(3) non-profit dedicated to the preservation of video games, their history, and related physical and digital materials]
• dataterm.digital - all things cyberpunk, novels, games, ttrpgs, techno, VR, inline skating
• slrpnk.net - solarpunk, green energy, no lawns, composting, farming, climate, DIY, anarchism, vegan, birdwatching
• lemmyfly.org - aviation related communities
• lemmyrs.org - everything Rust language
• poptalk.scrubbles.tech - popheads, Swifties, Britney
• aiparadise.moe - ai art, ai writing
• mtgzone.com - Magic: the Gathering (MtG)
• pathofexile-discuss.com - Path of Exile (PoE)
• dormi.zone - Warframe
• startrek.website - everything star trek
• possumpat.io - instance hosting communities for some niche interests and hobbies [possums, ff14, gundam]