The existence of the manifold doesn’t have to be the exclusive domain of antimatter.

Majorana Fermions could also exist within the manifold.  By virtue of it being it’s own antiparticle. A fact that is possibly a reciprocation of it existing within the manifold.

In the case of neutrinos this would also explain how a particle with mass can pass through everything with no interaction.

It doesn’t.

When we see it, we are seeing it manifest from the manifold.

As we will see as we explore the manifold further, particles can still exist at a point relative to our matter based space and travel to another point relative to our matter based space, but it is traveling within the manifold. A Neutrino would therefore be more likely impacted by the antimatter, than matter.