"IPCB_LayerStack_V7.InsertInStackAbove / Below on a layer already in the stack leaves it where it is, with no error." The fix goes through the stack manager's own move. Because every move applies the manager's copy to the board, the tool now refuses to move while the two copies disagree, since a move would write the stale values over the board. A silent no-op API is the same failure as a false pass. The author had to build the comparison from #187 first just to make moving a layer safe.