How does a panel get its current rating?
The panel may look identical to you but the thickness of the buss and the material makes a big difference where a inch of copper can handle 1000 amps per square inch verses aluminum of only 700 amps (NEC 366.23) so the buss material makes a difference it may look the same even be the same thickness but one being solid copper and one being aluminum with a plated copper makes a 30% difference. So a material difference or thickness, even the insulation used can affect the rating but we can’t really tell all of this with a casual observation.