Interesting, there only Prism beta builds for Sponge, or there further support?
Short answer … Yes for api 7
Long answer … There is a reason
So reading the prism 4 home page shows a interesting tail of the developer.
Prism 1 was made for bukkit, but then the dmca takedown of craftbukkit occured (which lead to the development of sponge 1)
So prism 2 came out as a sponge exclusive
Prism 3 started development, however the original developer left development and let it be developed by a different different developer who took prism 3 code and ported it back to bukkit (anyone getting Halo:CE vibes here?). The beta you find on the forums (must have been released before ore) is the original developers work
However due to popular demand the original developer is back, creating prism 4 which targets both bukkit and sponge api 8. While it looks like prism 4 doesn’t have any official download links, you can find the GitHub here
But do note that the last change to it was last year