Disable Altitude Check in Plan View of QGroundControl

I know this is a long shot, because this stuff is all “in development” and not really documented. Is there a way of disabling the altitude check when flying a predefined mission? At the moment, I have a GPS connected and position working in QGC, but when I try to create a mission and then fly it, the ROV attempts to dive or rise.
Obviously, I don’t want either of these, I just want it to ignore the altitude, because it sits right without using the vertical thrusters. I have tried messing around with the waypoint altitudes and mission altitudes and even tried disabling the vertical thrusters but nothing worked. With the thrusters disabled it sits at the takeoff point and I assume it is attempting to dive, but can’t due to a lack of vertical thrusters.
Has anyone had this issue before, or know of how to solve it?