I’m still hoping for an upgrade to the MC. I contacted them about it last year and was told basically that “if we want you to have it, we’ll let you know”. There wasn’t a way to apply for or request it.
As for CLIs, I had the $300 SL the first 3 years, and since then it’s been auto-CLIs to 700/1000/1300/1700/2100/2900 (current as of 11/2018). I use the hell out of it, carry balances sometimes, run it up, pay it down, and update my income about a week or so before the statement close date. They’ve been generous with me once they finally loosened the purse strings. All of those CLIs have happened since 2016. Spend and payments has been the key for me. Use it a lot, be 100% on time with payments, and UTI doesn’t matter - I’ve been at 90% before and gotten a surprise CLI. Long as you use it and pay, they will eventually start raising your limits and once they do it seems to continue fairly regularly.