I've recently done something close to this, and found Ceras[0] to be an excellent choice for the serialization layer.

[0] https://github.com/rikimaru0345/Ceras

I added a package for Ceras: https://www.nuget.org/packages/H.Formatters.Ceras/ I ran into some issues in testing where the data hash after serialization/deserialization does not match for Ceras. I added the package anyway, but this needs to be used with caution.