Sluggo,
I dont get it,
you say you are required to follow the AMA advisory (aka Safety Code) 400' to use the field,
but that safety code simply has you make a call before going maybe thousands of feet above 400

so, to be clear on what you guys do,
are you staying below 400' per some field mandate
or are you obeying the AMA code that allows you to fly as many thousands up as you can see