So if you had "substantially more" than that, you should be financially savvy enough to insure your accounts and pay for the insurance on them as a cost of doing business.
That's why we insure anything - in case something happens.
So if banks offer more insurance for a fee, I can't easily tell how to do this. My business banking account has nothing about such a feature, either online search or looking at the fees schedule.
I'd consider this obscure, even esoteric information. But I'd expect a CFO should know this. And I'd expect a venture capital fund would have an info sheet on avoiding consolidating deposits in a bank, given the 2008 experience. And yet... nothing.
But I think it's not common because there are other treasury management strategies besides "keep all your eggs in one pure-cash basket".