same functionality as VCL TAdvStringGrid.Autosize
The property only applies auto-sizing once during load time of the TAdvStringGrid. This functionality is already available in the TTMSFMXGrid:
procedure TForm1.TMSFMXGrid1ApplyStyleLookup(Sender: TObject);
begin
TMSFMXGrid1.AutoSizeColumns(True);
end;
This feature was implemented.