Whatever solution is found should DEFINITELY be made an optional one. I regularly work with a lot of image files, and I would HATE it if thumbnails constantly had to be regenerated. .thumbnails is essentially a cache for the file browser.
What RISK is associated with the .thumbnails directory? Only someone with access to your computer can see the files. At that point, I think you have bigger worries than some thumbnails.
Whatever solution is found should DEFINITELY be made an optional one. I regularly work with a lot of image files, and I would HATE it if thumbnails constantly had to be regenerated. .thumbnails is essentially a cache for the file browser.
What RISK is associated with the .thumbnails directory? Only someone with access to your computer can see the files. At that point, I think you have bigger worries than some thumbnails.