The conferences I submit to don't care if some of the background material (which is sort of boilerplate---but it is nonetheless necessary to state your assumpti

The conferences I submit to don't care if some of the background material (which is sort of boilerplate---but it is nonetheless necessary to state your assumptions) is similar across papers. Really, you couldn't do it any other way. I will say that academic (i.e., scientific) conferences should never include "recycled" or "old but interesting" material. There has to be some new research results. Otherwise, it's not science. The point of these conferences is not to entertain, it's to push forward the scope of knowledge.