In my view, the main advantage is that the frog fixing pins do not cause distortion of the sole behind the throat.
In Bailey pattern planes this is a significant issue.
The fixing mechanism also means that you can adjust the mouth, (frog position) in a few minutes without having to remove the blade and lever cap. It could be shifted, to suit the type of work being done, many times a day if you wished!
Alf, just breathing has a negative effect on the environment. Being alive takes its toll on the world so we all draw our line in the sand. And i do mean in the sand, we find out so much about the products we buy that we have to make new choices on the new information. I bought a Ibex bending iron from a well known luthier store in the USA and thought it was great that i saved myself £15. That was a couple of years ago. Now i find out that the owner is the leader of a white supremacist group. That £15 is sickening now. I won't be buying from them ever again.
No one can condemn another for buying anything because it is impossible to know all the facts about any given purchase and who hasn't bought something they know they shouldn't of.
Your purchase is helping a UK business as far as i can tell.