That's absolutely correct. With the redundancy with the AR7000 receiver (dual receivers so dual antennas), the orientation of these two antennas is important. But, if you happen to be flying, say away from you, and you are headed down-wind for a turn around for landing, and if you happen to get to the end of the range by pointing the TX antenna directly toward the aircraft, you could lose control of the aircraft. Then moving the antenna away from pointing directly, will consume some rather important re-acquire time for the RX.

Try to keep the antenna perpendicular to the aircraft path of travel. That's the safe bet.

CGr.