I've been contemplating this scenario and it occurred to me that the regular operations of this company (at least when I undertook it) are as a course, ie training. As training among the activity defined as Airwork, the charter requirements may not apply.
If this is the case, no seat belts, tanks, lack of floats amd disembarking in flight make much more sense.
This is merely supposition, does anybody actually know? While I've done the course, I can't write with authority about the regulatory background. I'd rather not get into a debate about whether it's actually charter or not, merely whether this is approved as such.
When I did it there was a serious hard@ss controlling eggress. I for one wasn't going to jump without this guy telling me I could. I've got a problem running the video, was she controlled this way?