I agree it is difficult to use the 4-bearing method unless it's a single ship. In fact, I find the 4-bearing method difficult and time-consuming in general. My beef with it is that it requires you to lie stopped for an amount of time submerged, when in reality due to buoyancy concerns this just wasn't possible. If using Stiebler's patches, this also becomes difficult in-game - you'll sink slowly if you stop. Also, all that time spent for a course and speed may be dashed when the target changes course/speed. That a lot of lost time standing still when you could be moving to get ahead of the target to mitigate the effects of a course change.
With the Ausdampfverfahren I find you can get all the necessary information with a rough estimate of target AOB. Even better, I find (though I'm biased
) the methods in my tutorial in my signature below very effectively deliver what you need and closely parallel historical procedures as I understand them. The 0-AOB method you mention is the foundation of the tutorial. Ausdampfverfahren is included there, as is another method, "Auswanderungsverfahren", which allows for getting target speed using rough range and timing bearing change over 1 minute, while moving.
It's good to see mention being made of tvre.org - that man (God rest his soul) did some great work!