Enable Point in Authoring Palettes and BPARAMETER. Pick parameter and label
positions, then create the native Point, XY grip and position expressions in
one undo transaction. Draw editor-only markers and clear placement previews.
Share graph append construction with Visibility so both types coexist in
either order. Allocate node, expression and edge IDs independently; preserve
existing objects, nodes and relationships and reject malformed/opaque graphs.
Reframe parameter, label and grip with the edited definition. Include authoring
positions in editor framing while keeping reference geometry extents unchanged.
Retain save/discard and parent saved-edit undo. Action association/evaluation
and parameter property editing remain separate milestones.
Validation: 10 targeted, 286 block and 60 dock checks passed (overlapping
filters). Appending a Point to an existing native graph passed DWG/DXF
roundtrips in all 17 local fixtures; old objects and original checksums stayed
unchanged. Real-view palette interaction and rendered marker/label verified.