Hi @robjennings, you have most likely encountered what I think is a bug:
I have added this to our bug tracker last week but do not have any feedback yet I am afraid.
In general, there is no global limit in n8n, but sometimes pagination does no longer work as expected (for example because an API might have changed without us noticing) or some API rate limit might kick in before pagination is complete.
You should always be able to use the HTTP Request node to directly send requests to more or less any REST API in such cases.