Three failed macaron batches finally taught me the right meringue temp

After batch 47 hit 87 cracked shells and crumby feet, I started logging every variable on a scrap of paper. My big surprise came at batch 50, where the winning difference was letting my egg whites sit for 15 minutes after separating, not the 5 I always rushed. The meringue peaked at a glossy stiff stage but stayed cooler, around 68 degrees F, which gave me smooth tops for once. All those hours fussing over almond flour texture were less important than just slowing down on the whites. I'm curious if anyone else tracks their own failure numbers or if you just wing it every time till something sticks. What's the weirdest fix that got your shells right?