It is already the task of judges to compare "apples" to "oranges" so I don't see a problem with DCI and DCA groups competing against one another.
Of course, the DCA groups would get beaten by most or all of groups that rehearse daily. But there are DCI corps in Open Class that have limited tours, and limited rehearsal time. I think Skeptic was very much in the ballpark when he placed the top of DCA around 25th place.
It would be very cool to see a DCA corps show up to the DCI quarters now that there is the new all-skate format, and see how they stacked up. There would be several challenges (show designed with DCA's rubric in mind, judges' first read, etc.) and the risk would probably outwieigh the reward, but it could be a hype for that group if they did well!