When using Mass File Upload, you have the option to customize its features based on your needs. However, if you're in a trial period, you won't be able to enjoy all the features.
As a trial user, there are certain limitations. You can only upload files up to 5 records and you can only access the Search Mode. This means you won't have access to the unlimited upload feature.
Additionally, some advanced features like List View, Advanced Search(SOQL), and CSV Upload are not available during the trial. To use these features, you'll need to Subscribe to the Mass File Upload.