I’m not completely clear what you’re talking about. The Edge> Bridge> Edges function creates quads. The Edge> Close Holes function will create tris. You could close the gap bits at a time with the edge> bridge function, or you could close the gap and then eliminate the tris after the fact with functions like Point>stitch, Point> Bridge > two points, Edge>Delete, and Edge> Split.
It should be said though, you compared Zmodeler to a “normal 3D program”. There’s no such thing. There are only tools with different areas of focus. A traditional vertex level modeling program with more than a decade of development in that toolset is likely to have finer control in that area, but can’t sculpt dozens of millions of polygons on relatively modest hardware. As a first generation tool, Zmodeler may be a huge step forward in shape making ability for Zbrush, but it doesn’t currently replace a polished vertex level modeler for vertex level work.
A knife is not a fork, a fork is not a spoon. If you really need a spoon, use a spoon.