The .NET driver is currently limited to C#6, released in July of 2015 (https://en.wikipedia.org/wiki/C_Sharp_(programming_language)#Versions). Since then, C#7.0, C#7.1, C#7.2, and C#7.3 have been released, all of which contain various developer qualify of life improvements (i.e. syntactic sugar) that we should be able take advantage of without raising the minimum .NET Framework/Standard version we are targeting, although some additional research may be needed.