Yes, printing a target for profiling on any printer requires turning Printer Profile "OFF" in Qimage and also turning color management off in the driver settings.
I suppose in that case I'm out of luck for trying to have my own profile made — I can't control what they do with their drivers as they run the high-volume machines. They do have a "no correction" option, which means they don't try to enhance customer images in any way, but I doubt it means they're switching off color management entirely. I suppose getting to the bottom of this calls for sundry permutations of how an image can be sent to them.
• sRGB vs AdobeRGB vs the Dry Creek profile
• Relative Colorimetric vs Perceptual
• Black point comp. on or off
The good news is, at least the prints are pretty inexpensive.