Why is file sharing not available in chat between external users (federation)?

[mikkele]

Technically they both require having OneDrive with settings that allow the option "Specific People"

If they don't then get an error, but otherwise are there other reasons why this is not available?

[#2 · Accepted solution]

They require OneDrive within the resource tenant, not to mention the number of compliance-related issues being able to do this would cause.