Tumblr is honestly the hub for any Floyd x Veneer stuff that feels properly exclusive. You find writers there who post snippets as they go, threading them together over weeks, and the interactions in the notes become part of the story. There's this one blog that only writes 'missing moment' vignettes for them, and you'd never see those anywhere else.
I also lurk on a specific Dreamwidth community that's locked and requires an invite. The content there is wildly different—super introspective, less plot-driven, more about their dynamic in quiet moments. It feels like a private archive, which is part of the appeal. You won't stumble on it via Google.
Discord servers are another big one. I'm in two that are centered on this pairing, and authors will drop WIPs or finished one-shots in dedicated channels before, or sometimes instead of, posting them elsewhere. The ephemeral nature of it makes it feel exclusive, even if it eventually migrates to AO3. I kinda prefer the messy, immediate reaction you get in a Discord thread anyway.