The API limits are independent of the plans. In other words, SeaTable Cloud Free, Plus and Enterprise are subject to the same constraints when it comes to API calling limits.
We deem that the API limits are sufficient for most use cases. If you run into the limits, then you should review your code first and seek to reduce API calls.
If you have exhausted your options to improve the script, SeaTable Dedicated, the premium hosted solution, offers higher limits. You can also self-host and up the limits in your system.