trailingImmovableColumnCount property
Contains a number of columns at the end of the screen (right) that other columns will not get moved past. Keep in mind, being within this range does not prevent a column from being moved by starting TableColumnControlHandlesPopupRoute for it.
Can be changed at any time (except SchedulerPhase.persistentCallbacks).
Implementation
final ValueNotifier<int> trailingImmovableColumnCount;