--skip-useless-pick

When the slicer exports a plate to a .gcode.3mf, it normally renders two auxiliary thumbnail images for each plate: a "top" image (an orthographic top-down view of the plate's objects) and a "pick" image (an object-color-coded version of the same top-down view, used to identify individual objects in the GUI for selection). --skip-useless-pick is a boolean flag, defaulting to false, that suppresses rendering of both images under specific conditions where they serve no practical purpose.

The suppression logic applies independently per plate and triggers when either of two conditions holds: the plate contains one or fewer printable objects, or the plate contains more than 64 printable objects. The first condition reflects that a pick thumbnail only has value when there is more than one object to distinguish between. The second condition avoids the cost of rendering what would be an extremely dense picking image where per-object color identification is impractical anyway. Outside these two ranges -- plates with 2 to 64 objects -- the thumbnails are rendered normally even when the flag is set.

For single-object plates the flag has a secondary effect: it also sets is_label_object_enabled to false in the plate's 3MF structure, disabling the label-object feature for that plate. This secondary effect only applies when slicing is also performed in the same run; in an export-only invocation that does not invoke the slicer, thumbnail suppression still operates on the same count thresholds but is_label_object_enabled is not modified. Both the thumbnail skip and the label-object suppression are computed at export time after slicing completes; the actual G-code toolpaths and print parameters are unaffected.