http://www.doctorofcredit.com/chase-pre-approval-branch-frequently-asked-questions/
http://www.doctorofcredit.com/ensure-youll-receive-pre-approved-offers/
Above are the links to the FAQs and data points for the Reserve. The second link is how to make sure you are able to get a pre-approved offer from Chase.
There are only two ways around a 5/24 denial that doesn't include the count for AUs on a recon call. There are countless data points of those who are way over 5/24 with no AU cards and got the dreaded 7-10 day message on their application. Then they went into a branch and asked if they had any preapproved offers on their account. Online offer on your account are not the same you have to check in the branch. Those who had one were able to apply and get the card.
The other way around 5/24 is if you are a Chase Private Client. Make an appointment with your banker and have them apply and call recon on your behalf. Most CPCs have been approved. I have seen a couple of data points where one wasn't approved so it isn't a guarantee. Those who went the CPC route were able to join CPC are reporting that they were able to do so without going "all in" on the amount Chase states are the requirements and you can negotiate the fee should you decide to let them manage anything. I have read that letting them manage your funds is not a requirement to become CPC.
My own datapoints for those considering: DH and I were both at or over 10/24 and non were AU cards. I pulled the trigger before I saw datapoints that 5/24 was being enforced. Got the 7-10 day message. Called recon twice and got the hard denial twice for being over 5/24. Checked to see if we had preapproved offers in branch and had none. Read the datapoints on CPC, ran the numbers to compare what we were currently doing with another firm. Decided to explore that route. Made an appointment with CPC banker the day after officially joining CPC. Since I already had a denial on my app and it had been past 30 days the banker did DHS app first to see how it would go. The analyst noted being past 5/24 but said they'd see what they could do for him since he was CPC. DH moved around some existing credit lines and was approved. The CPC banker had my app ready to send once we got the nod and hit submit. The analyst shifted around some of my credit lines and I was approved. Got my card 2 days later. CPC banker called me to inform me that they were out of metal cards and the plastic one was temporary LOL. I told him I was aware. Hope this helps.