For composites, Magnelite is a multi-step process. It is dipped in a conductive primer, a sealer, the pyrogen, a sealer, and then left to dry. If you stopped at the conductive primer, you could use the igniters ti light small BP motors, but for composites you continue on to the pyrogen step.
In theory yes, you could "double-dip" any commercially made igniter in the magnelite product, but there would be no real need to. I would stay away from using ematches for igniters, as they are low current and ignite very easy...unless of course you were clustering, where low current igniters are great for clustering and airstarts. If you do use ematches, keep the ends twisted together until ready to use, and do not install the igniter till you get to the pad, which I believe is standard practice.
For what we do, the only dumb questions are the ones that don't get asked...
Oh and don't take my word for it, as I have been known to be wrong. I am just passing along what I think I know.