As of I don't remember when, Python now guarantees the insertion order of dict, but there was also a older way by using collections.OrderedDict(). It looks like somewhere, there is a call to sort the keys before making the UI grid in the Analysis Indexes pane. If the user submits an OrderedDict type to .add_entry(), that sort should not happen.
index.add_entry(func, collections.OrderedDict({"Jump Density": jump_density, 'Byte Density': byte_density}))
Notice that there is a sort keys happening at one stage before the index columns are drawn. I have tried switching the order to see if there is some reverse happening, but its a sort.