I would LOVE to be able to add a third line of metadata to each thumbnail, so I could see the file size in KB/MB. Now, I come from Bridge, and I'm SUPER new to LRC (because Bridge doesn't run natively on my Mac Mini M1, Lightroom does, and M1 has been out for a year), and there may be a good reason for this, but if you can see the dimensions, maybe you can tell the file size. I can usually tell if the dimensions indicate an image that's big enough, but that's too much thinking. LOL
As a graphic designer and web designer (and photographer, somewhat), the image file size I need for a brochure is going to be exponentially higher than for an image going onto a website. To be able to quickly reference the file size would be invaluable.