I’m a commercial electrical project manager and I’ve never seen a spec call for 90C rated breakers. I bought dozens of panelboards last year from multiple manufacturers, including Square D.

You also need equipment lugs/terminal blocks/wire nuts rated for 90C.

I’m not saying 90C rated parts don’t exist, it’s just uncommon enough that you select wire based on the 75C column by default, even in a commercial setting.