Feature request: show thumbnails only for image files

Currently, there are 3 options for showing thumbnails in the Thunar settings:

• never
• always
• only local files

This is a feature request for adding a fourth option, or a separate option below it (like for size), for only showing thumbnails for image files. Use case: I find thumbnails for text and spreadsheet files to make it more difficult to find the right file (because seeing file type is less easy). But for images I prefer to see a Thumbnail.