Hiya Ohio43.
Now that AH2 doesn't require to click on the target of the clip board. Once you set the calibration, the only factor you need to check is the actual air speed on E6B. As far as your actual flying speed (E6B indicated speed) matches to the calibrated speed, the eggs will hit the point where your cross hair indicated. Altitude doesn't matter anyway.
Also, I observed that so many bomber pilot just drop the bombs at full salvo, which I never did. In the bomber I always set the salvo at 1 (one). This is especially effective when you bomb the target such as city, AAA, Radar factory, town, etc. (I have never done the 200-300ft F3 view bombing sortie) One formation of B24 will easily hit the target, say, city, something more than 450,000 points with over 700% hit percentage.
When ever I fly bomber sorty, I do it as good-old-day method, with 20-25K, 1 sorty usually last 30 min or so to deliver the bomb and rtb.
Hoping this will help at least some idea.
Regards,
Ryusei