has anyone tried or heard anything about the Monroe Institute's Gateway Process?

I started a thread about this a few months ago 

https://www.dharmaoverground.org/discussion/-/message_boards/message/26190377

since then I fooled around a little bit with binural beats after finding a few good meta studies on them (iirc it's linked in that thread I posted). What I found was that doing something like 200hz and 4hz would consistently get me into these very relaxed peaceful states, almost instantly, and sometimes there would be hynopgogic imagery. I found also using something like 7hz (can't 100% remember if this is what I was doing), would usually bring my mind into piti buzzing concentration states

Marc Leavitt's book Enlightenment begins with a retreat at the Monroe Institute. From the book description:

"This story centers on the peak period of my spiritual journey just after returning home from a weeklong meditation retreat at the world renowned ‘Monroe Institute.’ I had been home less than a week after attending one of their advanced programs when, without warning, I began to have profound Visions while living out my day-to-day life. I could be taking a walk with my wife and daughter or going about my daily routine at work when I would find myself spontaneously thrust into a vastly more expansive perspective that placed my entire world in a wholly new context."