You say "Correct", but Toast works the opposite of the person you're responding to. They charge the same fee regardless if it's a debit or credit card. They charge based on the network, and most debit cards in my experience use the Visa or Mastercard network. Yes, this is contrary to the Visa/MC terms, but I've never seen it enforced.

https://support.toasttab.com/en/article/Are-customers-charge...

It’s not just community banks or credit unions. The cap is $10 billion in assets.

There’s a whole industry of mid-sized banks just below that which are offering their services as sponsor banks to fintechs that want to earn the orders of magnitudes higher interchange rates while still getting debit acceptance/less surcharges and being allowed to offer a debit product.