I too am like Marvin.
I dont make a double reed. I dont like them (like you), I dont use them, and I have not spent hardly any time trying to learn them. Customers that cant live without a double reed, I just have to explain that I dont make double reeds, and try to help them get to someone that does make a good double reed.
I have messed around with a double a little bit (couple hours one time) as I have a friend that just thinks he has to have a double reed. Never got even close to something that I would consider good enough, and he didnt think much of it either. I used that to show him, you dont just throw a second reed in there and voila have a good double reed call, as well to show him, I did not/do not have the knowledge to make a high quality double reed. Some day, maybe Ill play with it more... but probably not.
For me, the last thing I want to do is make something Im not fully versed in, just to make a sale. I imagine the back lash down the road would not be worth the short term profit of selling a call.
I too try and work with them to help them get better at calling so that they can run a single reed, and many times they will start their migration to a single reed right there and then to take advantage of the added range and capability. But there are always those that want what they want, and thats all that they want. And you cant fault em for that... and thats when I try and make good recommendations for another call maker who does handle double reeds.
Good luck in what ever you decide.