[Pisces]

There is a maximum bearing in the sense that larger and lower than 90/270 bearing produce less of a speed component across the line of sight. With the target on your beam (90 degrees to your bow) the speed component across the line of sight is the largest. So if your speed is not sufficient to match the 'speed across' of the target while it is on that bearing then you'll never get a constant bearing. It's going to outflank you and the bearing to the target will slowly drift to your bow.

The target speed across the line of sight are equal for AOBs that are equally far from 90. So a target closing with AOB 60 will provide the same speed across the line of sight as it would with 120 degrees moving away. AOB 30 would be equally fast as AOB 150 moving away. The difference with less than 90 degrees AOB, as opposed to larger than 90 AOB, is that the 'lesser' will have the bearing drift rate increase due to closing distance. Whereas the 'larger' will have this drift rate slowing down, due to increasing distance. So if you cannot match the speed of the target across the line of sight when it is on 90 then you should find other ways to speed up or forego this method. Then the Auswanderungsverfahren will work better, as it relies on the bearing drift to get a result.

As far as gyro angle goes, I do not immediately see your point with the later part of your example. A wide gyro angle does require a roughly accurate range setting. But only at the closest of ranges will this torpedo turn parallax will it have the largest effect. At close range the target appears the largest in size, so it wil somewhat mitigate theses chances for a hit. But I would not fire without some roughly accurate value for range to correct for the torpedo turn offset curve.

P.S. A bearing on 40-42 is not constant. I doubt you had a constant bearing solution for this method to work. Also a moving away AOB is a clear indication you are firing from a disadvantageous position. You better re-position yourself for attack.