I can't say how well or why they'd work, but I'm almost certain people have done that very thing, and it worked well enough, and I believe they call that an "ice cream cone" airfoil. If you think about it, it looks like an ice cream cone on its side.
A guy in soaring made a whole series of profiles that had straight to and bottom rear sections, although they were cambered, not "symmetrical" (zero camber is the proper term).
His reason was repeatability, and ease of production. They work as good as the Selig's and European origin RG series of the day, for what they used them for (35oz/sq ft wing loading slope airplanes).
I don't think wing profiles are super critical for u control planes. That being said, that doesn't mean you would never notice any differences between them.
Make your ice cream cone airfoil, I'm sure it will work well. Just make sure the other design parameters are in the ball park.