Since I got a good night's rest, I'm revising my request. Instead of always starting the groove at 3500', I'd say start the "groove time" counter once the pilot has rolls wings level within 5-10 deg of final bearing IF they have already called the ball (manual or auto). I'll fly some passes and find out what HUD TCNs correllate (for FSX fliers) and their approximate display on your debrief screen in feet (so you can build a window). Tonight, I'll fly passes, saving an FSX screen shot and the accompanied vLSO debrief window for each pass. Then we can work out a "groove time" 15-19 secs that will ALLOW for the user to get an OK pass if they roll wings level onto final bearing in that 15-19 sec window.
Once that "groove window" gets figured out, I'm guessing you'll need to revise your debrief window to read some like this:
600' - AR; 1500' - IC; 2300' - IM; 3100'-3600' - X; 4000' - BC; 5000' - BR
And instead of a solid lines for the start, use dashed lines. This would make the start variable, a window, as it should be for each pass.
Here's another video that adds to what I'm saying:
(you see just after 5000', Paddles gives a BR (ball request)... pilot answers at 4000' and LSO final reply finishes at 34-3300'.. and thats and 0:10 secs... he hits the ramp at 0:27)
(granted this video and the video I used before are CASE III approaches, but they show when the LSO goes out for a BR, when the pilot responds, LSO final reply and the start of grading. So transposing, Case I, ZIP LIP, the vLSO BC should be around 4400' and the grading should start ["roger, ball"] when the pilot rolls wings level and approximately on final bearing.)
I'd also add, if you don't already have it (I think you do)... if the pilot rolls wings level onto final bearing and doesnt have a ball (too high/too low to be visible), they get a "waveoff, pattern". As well, once all this "groove time" stuff is worked out, you can add "waveoff, pattern" (Case I) if the pilot doesnt roll wings level inside that "groove window".