Yeah, I am worried that I am hitting Chase a little too hard. Disney Visa was 2/2015, Got a CSP in 2/16, closed a year later. SW cards were 6/17. CIP 2/18. So it was pretty steady but you're right that 4 in six months might be overkill. Plus, my credit limits with Chase are crazy high, although I will be closing those SW cards this summer, so that would help.
DH is also 3/24 currently plus the CIP he was just approved for. He just closed a CSP he'd had since 1/16. Arrival+ in 4/17. Two SW personal cards in 9/17. We are in very similar situations.
I like your suggestion except that it requires me to be patient and wait for that CSR. lol. But that could really be for the best. I am not sure what AMEX biz cards are out there, might have to do some research. Maybe SPG but I just missed the increased bonus and that all seems very up in the air right now. I have never really thought that MRs would be great for us because we value hotels over flights and hotel partners are limited. I would love to be proven wrong, though.