Wait, you almost ordered a cooler that wouldn't fit your motherboard? That's wild because in my experience, even checking specs can be tricky with all the clearance issues around VRMs and RAM. I've seen people miss that and end up with a cooler blocking the first PCIe slot. Your mileage may vary, but those checklists are more crucial than some builders realize.
Totally agree about those checklists being crucial! Your point on VRM and RAM clearance is spot on, I learned the hard way with a dual tower cooler that technically fit the socket but overhung the DIMM slots. Had to return a motherboard because the cooler's front fan would only clear low-profile RAM, which I didn't own. It's those extra few millimeters you don't think about until it's too late.