I have go with gaps method, which is a mix of many. This tends to be the case with me and others. Each method as a place to be used it.
If its dark or really foggy, I will use hydrophone to plot course and speed of target. If I am visually able, I will do same but with periscope. If I am really close enough, I use clock to take speed use stadimeter to take range and use my own judgment to take AOB, which is pretty much the aspect ratio way.
I have never learned 4 bearings method, I'm sure when I do it will be added into my methods.
I've made a quick formula card I also use for, quick attacks.
You still need your heading and target heading, AOB is quickly calculated and easy changed if needed. This is for a close range to medium range attack.