The correct filter string to exclude authoring templates should be -authoringtemplate::"Template Title 1 (note: authoringtemplate is all in lower case)
Additionally, all the possible fields that can be used within the filters can be found by inspecting the seedlist itself (eg: directly viewing the seedlist URL within the browser).
The id attribute (which is case sensitive) of each wplc:fieldInfo tag indicates the fields that can be used as a filter in the search query.
eg: authoringtemplate, contentPath, parentcontentpath, name, etc
Additionally, all the possible fields that can be used within the filters can be found by inspecting the seedlist itself (eg: directly viewing the seedlist URL within the browser).
The id attribute (which is case sensitive) of each wplc:fieldInfo tag indicates the fields that can be used as a filter in the search query.
eg: authoringtemplate, contentPath, parentcontentpath, name, etc