When sharing files, there are a few things that don’t share well.
Tools. If a user created a custom tool, I don’t have that tool in my library. A way to add it would be helpful.
Fonts. Same issue. If someone else used a font I don’t have, CC uses a different font. A way to at least see the information about the font so I can find & install it would be nice. I know I’ve looked in the old text version of the .c2d file & found the font info. Perhaps on the Text dialog it could show the info for the original font??
Images. Looks like background images get imbedded. I thought at one point I had seen background images disappear on reopening a file. That may no longer be a problem.
I’m sure these would be useful tools for support as well.
I’ve mostly encountered these issues when trying to help someone with a problem. But also in doing design work for others, I have to make sure I include tools & fonts when sending a file.