I’m scanning the box art from my own copies of some big box PC games I own as they’re often better than the automatic images. I also contribute a lot of scans to BigBoxDB.com, which prefers TIFF images. Right now, I have to run the images through an online converter before I upload them because the site seems to only accept JPG and PNG images. It would save me a lot of time if TIFF support was added. The images don’t have to be retained on the site as TIFF as I know they can get rather large and it could convert them down on the back end, but it would be nice to be able to not have to pre-convert them all first. Cheers.
Sorry, it is unlikely that we will support TIFF for image uploads.
I must say, it has been over 20 years that I heard someone mention TIFF for images 
It’s still the standard for high-quality scans for archival purposes.