Let's take this one step at a time.
First step: Get yourself back under 5/24.
1. From your DH's account, SM Chase to request removal of you as an AU on his CSR. After DH receives confirmation that you have been removed as an AU on his CSR, then...
2. From your Chase account, send an SM to have Chase remove the CSR AU account from your credit reports at every bureau to which Chase reports, and throw in the line that you have been removed as an authorized user on the account, and you are not and have never been financially responsible for the accounts. This can take a few days. Once you receive confirmation that the AU account has been removed from your credit reports, double check with Credit Karma.
The big issue is removing the CSR AU account will only drop you to 4/24, leaving you only 1 slot for a personal card from any issuer. If you are seriously considering dipping your toes into Amex Membership Rewards points, you'll burn that 1 slot you recovered fast, before you've had a drink from the CIPpy cup.
My concern is even if you were to drink from the CIPpy cup, you probably do not have enough time to accumulate 280k UR in 4 months. You have time for, at most, two sips. It looks like your DH is 5/24, so he can't be your P2 with Chase. And without "supporting" each other, that cuts your earning potential significantly. If DH still has his CIP, he could "support" you to your own CIP once you're back under 5/24, and that'll get you some extra points. I recall last year
@SouthFayetteFan and I laid out a solid roadmap for you (and reluctant DH) to earn URs from Chase business cards while preserving your 5/24 status. What happened? You kind of disappeared.
Now it's crunch time, and you need to decide what to do. You don't have much time.
If you're going to go with any Amex cards, please run it by us first. What you wrote here? Don't do that.
Amex has a lot of offers available via a variety of channels and methods. However, Amex's signup bonuses are generally once per lifetime, so if you apply for a card you're stuck with that offer and you typically will not get another bonus on that card again. So you want to make sure you get the best offer possible. Again, there are a variety of ways to get the best offer, which sometimes involves calling into Amex, or using incognito method on your browser to pull up higher offers, "supporting" yourself or your spouse using Amex cards you already have.
What Amex cards do you and DH already have?
The 35k MR signup bonus on the Amex Gold card is not even the best offer out there. You can pretty easily pull up a 50k MR SUB offer. If you had gone ahead, willy nilly, and applied for the Gold card, you would've been stuck with the 35k MR SUB when you could've had 50k MR. And you would've added a personal card to your 5/24 count before you decided whether you want to stick it out with Chase, or go with Amex. Again, with the Gold, the 4x MR groceries bonus category is nice but it's not going to get you to hundreds of thousands of points in 4 months. You need to stop focusing on category bonuses and look at signup bonuses.
Something you may want to consider: you could stick with only Amex business MR-earning cards, earn some serious MR bonuses (but with some serious MSRs and AFs), and preserve your sub-5/24 status. You can call in for the Amex Business Platinum for a
100k MR/$10k MSR/3 months offer. Then use the Amex Biz Plat to "support" yourself to a Biz Gold for a
50k MR/$5k MSR/3 months offer and
15k MR support bonus. You could also use the Amex Biz Plat to "support" yourself to the Blue Business Plus for a
10k MR/$3k MSR/3 months offer and
15k MR support bonus. You could use your Amex Biz Plat to try to "support" your DH to the personal Platinum (rather than having him apply for it directly), because this way DH may still get the
75k MR SUB, but you'll get a
15k MR support bonus. You can add that up.
But a word of warning. Starting last summer, Amex implemented a system to crack down on customers that they (their algorithms) have identified as "gamers," customers who exhibit a pattern where they open a card, spend on it to meet MSR and get the bonus, then drop off or stop their spending on the card and eventually close it. If you've been flagged for having this kind of "history," Amex will display a pop up warning when you submit an application for a new card telling you that because of your "history" you're ineligible for the bonus even if you
The bonus denial pop up means Amex has flagged you as, essentially, an unprofitable customer who might be only interested in chasing bonuses and not putting any ongoing spend on their Amex cards. It’s typically targeted at applicants who have signed up for Amex cards, met MSR, pocketed the bonus, and stopped (or even just dramatically dropped) spending on those cards. The only cure anecdotally is putting some spend on your existing Amex cards may get you back in Amex’s good graces, and get that pop up to go away.
Gone are the days of picking up an Amex card, meeting MSR for the bonus, and sock drawering it until it’s time to close it after a year. That will land you on Amex’s naughty list fast, and you’ll be stuck in bonus denial pop up purgatory until you put some (possibly serious) spend on your existing Amex cards. Amex will gladly approve you for cards, but they want to see you putting regular, consistent, and ideally high levels of spend on their cards if you want Amex to keep approving you for new cards with bonuses. Otherwise, they’ll figure you’re in it only for the bonuses and flag you as a “gamer.”