I had my Amex CM for just over a year. I did a request a few weeks ago to take it to 30K, 3x would have been 36K, but I was scared to ask for it all. Got the 7-10 day message, which I knew was because I was not 180 days since my last 3x CLI.
Got an email from them a couple of days ago congratulating me on my year so I tried again, but only asked for 2x, instant approval to 24K. Kicking myself for not trying the 3x, but was a little gun shy and I have not really used it that much since I have other cards at 3%. Not that bummed because at 24K its now my highest limit card and they have bumped my limit 20K since I got it at a 4K SL. All an all Amex has been good to me.
Congratulations!!! AMEX is the BEST in my book. This post by you is very reassuring because I just met my 61st+ day on a new AMEX Hilton Aspire card with a low starting credit limit of $4,000 compared to the $11,500 starting cl for their Delta Skymiles Gold card they approved me for on the same day -- weird. They actually approved me for 3 cards in total (AMEX Rose Gold NPSL) on the same night in early July of this year.
So, a couple of days ago I requested a CLI on the AMEX Aspire and requested the $4,000 to $8,000 (didn't want to try the X3), and received the dreaded 7-10 day response. All AMEX cards are paid in full as well, but I have 5 total inquiries on my Experian since July 2019. My gut is telling me it's a denial since I've been approved for a lot of new credit, but hope there aren't any grave implications for requesting. FICOs are all in the solid 700s, but I worry if I tried too soon.
At least your post gives me hope. If I get a denial letter, I will just wait on them for an auto CLI. In past, I've been through a FR and while it was painless, I just don't want to deal with that again.