NEI Integration is two things-- a playground to try out new types of NEI handlers, and a place to put NEI handlers if I somehow can't get them into the mods they were made for. The mod aims to stimulate other mod developers to add NEI handlers to their own mods.
Requests for additional NEI handlers will gladly be accepted. Just create an issue, and I'll see what I can do.
If you are a mod author and want to migrate some of these handlers to your mod, please do so! That's one of my goals. Just try to follow these guidelines:
Alternatively, if your mod is open source, you could just ask me to do a pull request.