Hey Håkon!
Actually, to convert objects you don’t need a reference to Objects. This is because Speckle.Core is capable of dynamically loading kits. This feature is there to support 3rd party kits as well.
See how our ConnectorBindingsRevit.Send does it:
Where the crucial lines are:
var kit = KitManager.GetDefaultKit();
var converter = kit.LoadConverter(ConnectorRevitUtils.RevitAppName);
converter.SetContextDocument(CurrentDoc.Document);
var conversionResult = converter.ConvertToSpeckle(revitElement);
You could of course have a direct dependency on the converter and object classes if you wanted, but would lose the flexibility of supporting multiple kits.
Any other questions just ask! (I’ll edit your post title for clarity 
)