Reassign unit and panel annotations in Outputs settings
Renumber unit and panel labels in your outputs using one of two modes, confirming first because the change cannot be undone.
Outputs > Setting > Reassign unit/panel annotations has two modes, 'On proximity and unit type' and 'For optimising CNC file names in barcode'.
Outputs > Setting > Reassign unit/panel annotations asks to confirm first, because a unit's label (e.g. C5) may change in every output and the change cannot be undone.
Outputs > Setting > Reassign unit/panel annotations renumbers the labels without gaps.