Many,Many people in my world will start a horse in a Hackamore.
They are skilled Hackamore Reinsmen and understand the pros and cons.
I do not exclusively use just the Hackamore ,but because the title of the thread was the adjustment of the Bosal I limited the discussion to that.
There is a history to the Hackamore and that is what the NRCHA is trying to keep alive.
In the very early days of the Spanish Vaquero the snaffle was not as common as it is today and most of the horses were started in the Hackamore.
"The greatest strength is gentleness."
- Iroquois Proverb