Hi Talvi, I like the calculations you did in your last post. I wasn't so organized as you, but I did do some experimentation with how many TT beats are optimal for me when I push-off the wall. At Andy's suggestion (years ago), I set my TT to 0.6 S and use 2 beats/arm stroke, because it helps me coordinate myself to the TT better after push-off.
This varies some from day to day, and also with TT setting, but at 1.2s/stroke (what you used) I was surprised (and dismayed) to discover that I got my fastest lap times with 3-4 beats after push-off. At 0.6s/beat, this means I am using a lot shorter push-off than in your calculation. This may mean that I am not very streamlined, but it is what it is. So my suggestion is try playing around with shorter push-off times to see what it does to your times. Your SPL may go up, since you are now swimming a longer distance per lap, but your lap times may go down.
I have also noticed that the time I actually take to turn around at the wall can vary. There are times when I hit the wall at just the right point in my stroke and the turn-around gets nicely integrated into the stroke, and other times when I feel like I am wasting time turning around and I can hear the damn thing beeping in the background while I do it.