Quilter currently supports a range of PCB layouts, from basic 2-layer designs to complex multilayer stack-ups with 10 layers or more. In reality, adding extra layers often simplifies automated layout for Quilter, as they provide more space for routing and power planes.
There's no fixed upper limit—Quilter can handle extremely complex multilayer stack-ups defined in your manufacturing profile, giving you the flexibility to meet a wide variety of design needs.