"more" usage likely means that they have a limited number of GPUs, and what models you get access to depends on how much you've used them recently, but also on how busy the GPUs are at this moment.

This is also how batching works for API users. If you don't need the results immediately, you can give them a batch with an attached 24-hour deadline, and they'll slot you in whenever they expect low usage, in exchange for better prices.