Yes, phone people are supposed to encourage solving problems with purchases.

The maximum seat pressure is greatly affected by how well the gallery pressure keeps the tappet inflated (removing slack from the VT and preventing crash landing of the roller on the lobe). This varies between engine models (those never built with hydraulic tappets are suspect), oil viscosity, the fit of the tappet body in the bore, and pump pressure.
I wouldn't run it with 180, because my OCD will keep me listening for crunchy noises. To me, being comfortable with the decision is really important.