ECN Forum Forums General Topics of the Trade General Discussion Area Panel Schedule - 10% Rule ???

You need to go to 408.14 and 408.15 for the answer.
A lighting and appliance panelboard is one with more than 10% of it's overcurrent devices 30 Amps or less, and the branch circuits connected to neutral.

It's only allowed 42 circuits (which you have)

They don't want to sell you a 60 space power panel.