geometry package or native registers for mid-document margin changes

geometry package or native registers for mid-document margin changes

The goal is to adjust text block margins partway through a document while keeping facing pages symmetric. Under standard LaTeX2e behavior, the geometry package manages dependencies between paper size and layout lengths automatically, but its support for repeated mid-document reconfiguration is not clearly documented. Direct manipulation of native length registers permits granular changes, yet edits after the first page is shipped risk asymmetric offsets on verso and recto pages.

Overlap with KOMA-Script classes adds uncertainty because competing layout definitions can shift margins unexpectedly. The decision is whether to rely on package options or manual register control for dynamic margin changes without layout drift.

Is geometry safe to invoke multiple times for different margin sets? Should native register changes be confined to a specific shipout boundary to preserve symmetry? Must geometry be disabled when using a KOMA-Script class to avoid conflicting layout definitions?