Trialectics sounds like a bad attempt to get out of postmodernity. The better way is simply to return to unity. Three is a good number since it turns an unstable figure like a square into a stable one with triangles, but dialectics already have that. I guess a trialectic could mean building tetrahedrons instead of just engaging in "progress" via the dialectic and I've used that concept creatively before, but enneagram doesn't relate to tetrahedrons in any way.