It would be just like “edit mode” in Blender. u can do a couple things with those vertices, like select a row, then double the vertices, to extend it. (Ik we have mask but it’s not as clean) this would help make more hard surface shapes. And would help a lot with thing like armour. And clothes.
It does seem as if people are using Mask in a few ways because of some tool missing in Nomad Sculpt.
Poly editor would be great . I think it would take an overhaul of Nomad’s sculpting engine to implement, probably not the easiest of requests, hopefully one day we see this expansion.