Right, I read this article last winter, when I was getting interested in Heavenly New Frontiers. I ended up buying lots of seed crosses with HNF, most will be blooming this coming year.
Are you making conversions yourself? I suppose, if you had a new conversion, you could trying crossing with known other ploidies, to determine its ploidy, rather than getting it tested. But that wouldn't identify Pentaploid I presume?