Using the Adapter classes, is there a way to limit the maximum number of rows returned when also doing prefetches?

Yes there is. When adding a path to a prefetch path one of the parameters is for the maximum amount of items to return. You can see more under the best practices part of the documentation.

IPrefetchPath2 path = new PrefetchPath2((int)EntityType.CustomerEntity); path.Add(CustomerEntity.PrefetchPathSubprojectCustomer, 0);