We are working out how to handle our purchased parts. Typically we use a lot of McMaster parts and the files get downloaded and used in an assembly. This quickly balloons our vault with files that are often only used once and are more likely to get duplicated than reused.
We can use them as virtual parts, however to update the BOM in the drawing and PDM we have to fill out the data card (preferable) or the custom properties (annoying).
The data card will show as the same format as the assembly it is in which is not the best format for a purchased part. It will lead to people missing key information in the data card.