I use exactly the same settings you do, and I understand the temptation, but I resist it everytime, until I can actually see the ship myself or, when it's real dark, my crew reports it.
I do most of my intercepting and hunting by hydrophone, get a rough estimate of targets course, do a quick dash on the surface for about 10 to 15km on a rough intercept course, listen again, get a good course and speed indication, then set up an intercept, submerge fairly early and stick up the scope when the target should be visible in the prevailing weather. If I can't see it yet, lower scope immediately and get closer, also minimizes radar exposure later on
same tactic for surface intercepts or decks awash attacks on convoys
I've never used wo assist couldn't tell you if it works