I sure hope someone responds to you because I was going to ask a very similar question!
We have a 12 week old (tomorrow!). I find that if I don't have him in his crib and ready to sleep by 1 hr 15 minutes, then he is overtired and tough to put to sleep. That means we have to start wind down at 1 hour on the dot, so we are really only getting about 15 minutes of fun, as I've been finding we need about 15 minutes to transition from fun/activity to bed time for best results. If I don't get him in his bed by the 1 hr 15 min mark I find that at 45 minutes on the dot he startles with a cry and I have to shush pat him back to sleep. However, If I have him ready to sleep by that time ( or even earlier) he goes right to sleep easily on his own, sleeps 1.5-2 hours without a peep. I've been worrying that our A time is too short, yet clearly he's overtired if we go longer than that.
Right now I'm boiling our Level 2 nipples because our E time has really started getting too long, and I think it's because he's ready to upgrade the nipple. I don't know if you BF or FF, but maybe that's something you could look into too. I'll let you know if the new nipples cut down on our E time and let us have some more A.