It doesn’t take an hour to preheat cast iron

FTA:

To preheat over a burner: Set your cast iron skillet over medium heat, ideally on a burner that’s roughly the same size or larger than the pan’s base. If your burner is smaller than the pan, rotate the skillet a few times during preheating to help even out hot spots. Give it 3 to 5 minutes to come up to temperature. Then, and only then, add the oil and let it heat until it shimmers or just starts to smoke. If you’re aiming for a specific temperature, use an infrared thermometer to read the surface directly. For gentler cooking tasks, such as sautéing onions or frying eggs, a surface temperature of around 400°F is usually sufficient. For high-heat jobs like searing a steak or pork chop, let the pan reach a temperature closer to 500°F.

To preheat in the oven: When you need a ripping-hot skillet to put a proper sear on steaks or chops, I recommend using the oven, which can heat the pan evenly while also making it exceptionally hot. Place the empty cast iron skillet in a cold oven, then turn the oven to 500°F. Once it reaches the desired temperature, carefully remove the skillet using oven mitts or a thick kitchen towel (it will be blisteringly hot, so make sure that towel isn’t even the slightest bit damp). …

(emphasis mine.) Ovens typically take 10-20 minutes to come up to temperature, and if for whatever reason your oven is already hot, it won’t take longer than what your oven takes to preheat to to get up to temp.

Either way, I typically start preheating as I’m prepping everything else.

And yes, I know I have an even pan because I not-infrequently make omelettes in them.