Update released.

When AllowMultiSelection is True and AllowSelection is False the AllowBigSelection property now controls the behavior whether multiple single selections can be done via shift+ctrl or ctrl.
When AllowBigSelection is set to False (defaults True) it is not allowed anymore and truly single selection.
That is that .SelectedRows can then return only 1 or 0.

@bincong, be aware that altering via .RowSelected(x) does not raise a MultiSelChange event.