When changing angle variant for external threads, the minor diameter stays constant, which, for me, is intuitive. If I make a 60° threaded rod and change it to 45°, it will still fit in a 60° nut.
On the other hand, the same applies to internal threads, which I find a bit annoying, because a 60° nut converted to 45° will no longer fit on a 60° rod. I think it would be better if, for internal threads, the major diameter stayed constant when changing angle variants.