Seafile Virus Scan configuration

Hello I have questions regarding two options from the Virus Scan manual page.

First option: scan_skip_ext
As it says in the documentation there are some file extensions that are ignored by default. How can I get rid of these default extensions so every file is checked?

Second option: threads
As its described in the documentation each thread is assigned to one file. but what would happen If a greater amount of files then threads needs to be checked? Will the remaining files be queued until the threads are free again?

Kind regards and thank you to everyone who takes his time to answer these questions.