I super love this feature, let me just say. I ran into no major issues, and only a couple of small things.

On loading json preview in development protocol, I got a warning:

Warning: Each child in a list should have a unique "key" prop.

I kind of think this is an artifact of the oddness of the json for the development protocol, because it on purpose doesn't have the "name" variable correct, so some show up as null?

Also really minor, but the development quadrant images don't show up on a white background. I'm not really recommending anything, because they download just fine, but I suppose an above and beyond solution could be to offer to toggle the background color for images, however I'm not convinced this is necessary.

Thanks @rebeccamadsen I've resolved those warnings.

When looking at this afresh I thought it also make sense to add the preview/download functionality to the Codebook.