I got the Amex Zync last August, and included both my part time income and grants/loans as total income (probably not the best idea). I was approved, and was cleared up to $4000 via the charge approval button.
Fast forward to now. I don't have a part time job as I'm taking more hours; however, I now receive more scholarship money. I checked the button again and was only approved up to $2500. This may be in part due to a high balance that I let report recently, which has since been paid off and the statement cut. But now I'm a little worried that they might FR me, especially since I'm about to apply for one or two more cards. Are they likely to FR me when I've had my card for 10 months? I'm making about the same as I was last August, but I'm not sure they'd count grants and scholarships as income.
Leave the charge approval button alone, live within your current means, don't be late on anything, or have new baddies show up on your CR, and you will be fine. FR's are rare, and even more so for people spening a couple thousand or less on their AMEX card.