Reply to Two xone k2s + external mixer

Has anyone hooked up two xone k2s to an external mixer and aggregated the soundcards? I currently have two k2s linked together but would like a dedicated external mixer with crossfaders and alike. Was believeing about buying a second hand xone 42 and setting up with the two k2s. Before buying I just wanted to get people's thoughts and opinions on this.
Ps I have sifted these community s for years to gather advice and ideas and find it an invaluable source. Keep up the good work everyone!