$250k/MONTH Spender Looking to Maximize Cash Rewards

I am a business owner and spend about $250,000 per month on business expenses through my personal card. Most of the spend is on digital marketing (i.e. Facebook, LinkedIn, Google, Microsoft, etc.). I am reimbursed on these expenses every month from my company.

I am looking to maximize cashback (i.e. I don't need miles or reward points). Currently, I use the Bank of America Visa Signature card (personal card, not business) which pays me 2.625% cash back on my spending. Are there other cards I should be looking at?

I have a friend who has multiple AMEX Gold cards and get 5% cash back but it limits out at $100,000. Ideally, I’d love to find a single card that pays higher cash back.

Current Card: Bank of America Visa Signature (personal card), Southwest Visa Signature (personal card)

Fico Score: 874

Oldest Account Age: 24 years

Chase 5/24 status: 0/24

Income: $400,000

Average monthly spend and categories:

- Digital marketing: $250,000/month

Open to business cards: Yes (note: I currently only have personal cards and no business cards)

Purpose of next card? Cashback