@jzissop -
What @btburnett3 is true; I was confusing the two projects (SDK and Couchbase.Extensions.Caching). The library that Brant mentions (GitHub - couchbaselabs/couchbase-aspnet: Couchbase Asp.Net infrastructure support) is an older .NET Full framework provider, but could be updated to SDK3 and it would work for your needs.
-Jeff