The main config for uSync is stored in the usync8.config file most of the main settings in this file can be changed in the uSync dashboard.

<?xml version="1.0" encoding="utf-8"?>

    <!-- handler sets -->
    <HandlerSets default="default">
      <Handlers Name="default">
        <Handler Alias="dataTypeHandler" Enabled="true" />
        <Handler Alias="languageHandler" Enabled="true" />
        <Handler Alias="macroHandler" Enabled="true" />
        <Handler Alias="mediaTypeHandler" Enabled="true" />
        <Handler Alias="memberTypeHandler" Enabled="true" />
        <Handler Alias="templateHandler" Enabled="true" />
        <Handler Alias="contentTypeHandler" Enabled="true" />
Setting Values Note
Folder Path to folder Location at which uSync will save and read the exported files
FlatFolders true/false Determines if uSync will store the files in a flat or structured folder structure
ImportAtStartup true/false should uSync run an import when the umbraco site starts up (default: true)
ExportAtStartup true/false should uSync run an export when the umbraco site starts up (default: false)
ExportOnSave true/false Should uSync produce an export when an item is saved inside umbraco (default: true)
UseGuidFileNames true/false Should uSync use the guid of an item as its filename, ensures there are no clashes in names, but makes it harder to manaually read what settings are in a folder (default: false)
BatchSave true/false when doing a large import, save elements in batches - this feature exists to try and circumvent issues that can occur when Models Builder is enabled as lots of saves can cause a site to restart.

for Handler Settings, see the Handler Docs