Sorry, I got carried away a bit, what should've been a short post turned into a big one and a self-named "method". Sorry for that, thought i was reinventing the wheel.
Fiddling with the range dial was just to demonstrate that range doesn't matter at all. I still set it tho to a reasonable value just in case the target sees me and changes course in the last second. I have only recently started using modified interfaces so being cooked up in the periscope view deprived me of seeing the TDC. plus the only way of doing the the TDC bearing changes was to change views or move the bearing dial by hand.
Until one month ago I was still plotting the solutions and transforming relative bearings to North-bearings with the wizz wheel. Then it just hit me while I was playing SH4. The American TDC is nice but the inability to link the AOB to the periscope is a deal-breaker for me. But while moving I saw the AOB becoming perpendicular and the rusty wheels started turning in my brain.
But this should still help newcomers to the game find manual targeting a bit more "predictable".