I also notice H. montana 'Praeflorens' ...and I believe
that has been changed to H. montana 'Macrophylla'? So am I opening a
new can of worms?>
I went through the same questions (still do), my
solution was building a database and cross-referencing the different names. It
is surprising how many suppliers use the old name, creating renewed
confusion with the release of their catalogues.