I think we mean the angle between one tack and the next, not the agle between irons and current direction.
Translating your numbers it would be 90-100 for tacking and 40-110 for gybing. (right?)

I think it's not about the telltales. You follow the telltales, true, but first you choose how high you want to go and set the sails for that, I think that's what we are talking about.

For the few measurements with iRegatta I've done, it seems that VMG (towards wind direction) changes little if I open the tacking angle a bit (say up to 10 degrees). Speed increase almost equals the effect of lower angle. And beyond that yo may go faster (though not a lot more) but slower towards wind direction. As said before, it changes with wind speed and conditions. It's cool to measure it, if you don't get crazy about it anyway.. Just set the wind direction and speed and forget about it, let the software capture the data. You can watch your speed every once in a while too and that's it. Then you download the readings and have fun again in front of your computer (in the office maybe..)