RE: DX11X Elevons and elevator mix
I don't believe there is that much difference between the DSX11 and the 11X sold in North America. When my 11X is set to Delta wing type, there is no problem with mixing the pitch to another channel.
Inhibit a channel, say AUX2, and call it your elevator that is not part of the elevons. Then just mix ELEV -> AUX2. In the program mix, ELEV refers to the pitch motion of the elevon. With this mix, the elevon roll action is not sent to AUX2.
Allan