I've been working on the "slow down and look ahead" thing and it's actually helping! My 3x3 avg was a little above 30s, and now it's a little under 30s. But on a good day when I'm being very mindful of looking ahead, I'm consistently getting ao12s around 25s.
Honestly I've been a little lazy about inspection. I take 5-10 seconds to plan the cross, and as soon as I have that, I just hit the timer. In fact I don't even plan the whole cross sometimes -- If the 4th edge isn't easy, I'll do a "I'll figure that out when I get to it." But I really should train in planning the first f2l case during inspection! I think it'd shave some seconds off.