I don't understand why you'd create a hub account.

I doubt any CC issuer is going to care much if your billpay comes from one account or three-five accounts. It just seems like an overcomplication and a major red flag to the hub bank, which it ended up being.

As for the $40k figure, I read that as he had his account open for six months and moved $40k in and out recently over a short timeframe - not that he moved $40k over 6 months.

I doubt anyone is going to say they are hitting Blue Cash hard if they only charged $7k a month.