There are a number of settings that can be set within miscellaneous.
Key items:
Enter a Maximum Text Content Size for indexed content in bytes to limit the size of a text based file.
Enter a Filename Boost to add a relevancy boost to a result thats filename matches the searched term.
You can hide entity groups from document details by adding them to Entity Groups Hidden From Document Details.
By default PCI and PII entity groups are hidden, you can add to or remove these groups.
When performing a search a Default Search Operator will be applied. Choose the Default Search Operator from the dropdown.
OR - Return more results for multi-term queries.
AND - Return less, more concentrated results.
Choose the the Query String Query Type from the dropdown.
By default this will be Cross Fields and won't likely need changing.
Check Enable Permissions for Entities, Metadata and Attributes to hide protected attributes from users the don't have access.