How do you go about disabling thumbnail generation for certain mime-types? We would like to disable the thumbnail generation for Office docs to reduce unnecessary conversions (and load), since honestly a small thumbnail image isn't very useful for a multiple-worksheet Excel file. I thought I would be able to just remove mime-types from the “anyToThumbnail” converter (source, but that didn't pan out and the thumbnails were still being generated. I even went and removed the same mime-types from the “any2pdf” converter, and that didn't help either (I think those are for previews anyway).

I'm not sure why this isn't working since I had previously added some mime-types to these extensions points to generate previews and thumbnails (for Apple keynote files), but removing items doesn't seem to be work. I'm thinking that the XML extension is additional to the source converters so if I remove an entry I add, it is still found in the source—correct me if I'm wrong.

My goal is to be able to selectively remove thumbnail generation for certain mime-types and then have a generic icon/thumbnail show instead (these could be the defaults in Nuxeo, although I would likely override those to something different). Any guidance would be appreciated. Thanks.