Hey Bill, welcome to the forum!
I have never played with a V Tail and have not owned a DX6, but I do have a DX9 and I'm pretty sure the relevant menu's are the same.
I had a look in the travel menu and it's mixed 100% and there are only the two control surfaces (REL & LEL). So it's definitely not a standard setup, but in the D/R and Expo menu, you can set each to have a different dual rate. My thinking just looking at the sliders is that if you raise the rudder and lower the elevator, you should be able to get them to even out. If you need more throw on the control surfaces and you are maxed out, you can go one more hole out on the servo, or one more hole in on the control surface, but I would suggest using some expo to soften those throws otherwise it could be twitchy.
The images below show the DR/Expo screen and it's very exaggerated, but shows how it works. Then there is the travel screen where I pulled the rudder then the elevator in full throws and you can see that the number is also drastically different. Hope this helps.
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