Spektrum DX6i can deffo do it, used to use it on my EDF Rafale, but not heard about the DX5 in that link though it mentions 'Delta wing mixing' so I'd say yeah .
Your right there is 1 servo for each elevon, and the Tx does all the mixing...
Awesome, what size models can these digital micro servos be used on?
Probably be around 1.2m wingspan. I'm assuming I would need normal size servos for something that size?