How are they placing this data? Api? Not possible to align disk tiers to api requests per minute? Api response limited to every 1ms for some clients, 0.1ms rate for others?

You're pretty forthcoming about the problems so I do genuinely hope you get some talking points since this issue affects, app&db design, sales, and maintenance teams minimally. Considering all aspects will give you more chance for the business to realise there's a problem that affects customer experience.

I think from handling tickets, maybe processes to auto respond to rate limited/throttled customers with 'your instance been rate limited as it has reached the {tier limit} as per your performance tier. This limit is until {rate limit block time expiry}. Support tickets related to performance or limits will be limited to P3 until this rate limit expires."

Work with your sales and contracts team to update the sla to exclude rate limited customers from priority sla.

I guess I'm still on the "maybe there's more you can do to get your feet out of the fire for customer self inflicted injury" like correctly classifying customer stuff right. It's bad when one customer can misclassify stuff and harm another customer with an issue by jumping a queue and delaying response to real issues, when it's working as intended.

If a customer was warned and did it anyway, it can't be a top priority issue, which is your argument I guess. Customers who need more, but pay for less and then have a expectation for more than they get. It's really not your fault or problem. But if it's affecting you I guess I'm wondering how to get it to affect you less.