I don't think the Caching Application Block would ever support that. Quoting Chris Tavares on his "Thinking About the Future of Caching Application Block" blog:
"With the upcoming release of the cache-formerly-known-as-Velocity, Microsoft has a quality distributed cache technology available. We’d be nuts to try and replicate all that work. We did an analysis of the APIs between our CacheManager
and the Velocity cache and came to the conclusion that wrapping Velocity in our interface would cost you a huge amount of capability, so we decided the best guidance was “use Velocity” rather than go through the caching block"
Here's the link on his full blog:
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