1¡¢why TMemTableEh can not support MouseWheelUp and DoMouseWheelDown?

in the unit DBGridEh,
function TCustomDBGridEh.DoMouseWheelDown(Shift: TShiftState;
MousePos: TPoint): Boolean;
begin
if ViewScroll and FDatalink.Active then //why is ViewScroll ?
begin
Result := False;
if Assigned(OnMouseWheelDown) then
OnMouseWheelDown(Self, Shift, MousePos, Result);
if not Result then
begin
if ssShift in Shift then
if ssCtrl in Shift
then FDatalink.DataSet.MoveBy(VisibleRowCount)
else FDatalink.DataSet.Next
else if ssCtrl in Shift then
begin
if (RowCount - TopRow - VisibleRowCount < VisibleRowCount)
then
FIntMemTable.FetchRecords(VisibleRowCount - (RowCount -
TopRow - VisibleRowCount));
SafeMoveTop(TopRow + VisibleRowCount);
end else
SafeMoveTop(TopRow + 1);
Result := True;
end;
end else
begin
if FDatalink.Active then FDatalink.DataSet.MoveBy(1
{Mouse.WheelScrollLines});
Result := True;
end;
end;

2¡¢the property "lookupdisplayfields" of the TDBColumnEh,Such as
property lookupdisplayfields is "ID;Caption;Code;",can you Add a
property which it show lookupdisplayfields by second text "caption",
such like TDBLookupCombobox'property ListFieldIndex.

3¡¢TDBGridEh can not support lookupGrid by different filter
Mode