as long as other instances haven't blocked federation with this instance you'll still be able to access it.
you will however need to find the communities first and subscribe to them to have them show up in your feed, as nsfw communities don't show up on other instances by default as far as i know.

!nsfw411@lemmynsfw.com is intended as a band-aid for this, but you can also visit this instance and find communities here directly and then sub from another instance.

https://lemmynsfw.com/post/25934

the workflow currently tends to include first searching for the community by url or by !community@instance and then visiting the community url on your instance by putting for example yourinstance/c/community@lemmynsfw.com in your address bar.

this instance also has a custom set of patches applied to make nsfw stuff more accessible to users, including those who aren't logged in.

speaking of, where does one find its source code?

you can't post direct links to redgifs mp4s, they only work for a limited time.

i was indeed asking about the patch, thanks

when the name is already in use it gets stuck currently.
might apply to other error cases as well. you can check if a name is used by visiting https://lemmynsfw.com/u/NICKHERE

porn is banned on imgur, this upload is already gone

there seems to be an issue with blocking communities. i've blocked a number of communities containing content i'm not interested in but they recently started showing up in the Local feed, such as https://lemmynsfw.com/?dataType=Post&listingType=Local&page=1&sort=New

since May 15: https://i.imgur.com/CFu72a6.png
iirc they started purging existing images a bit later, although plenty of them still exist.

for plain images I believe you can upload directly to this lemmy instance, there's an image icon next to the URL for creating posts.

for videos, i've seen a number of people use https://catbox.moe/