wow!
A user just came to me panicking about his CAD file. I took a look and noticed all the xrefs loading... and they just seemed to keep loading.
When it finally opened I saw what is shown in the image below.
So this leads me to two questions:
1 How many xrefs is too many?
2 What are you telling your users to do when xreffing? Overlay, attach or are you not managing this?