[Digimaster6662000]

Spoiler for LNs up to New Testament 07:

If you are going to shot each other down, then please examine the story closer. First, as to whether Accelerator can turn off Reflection. As another poster previously stated, NO. Accelerator uses a large amount of his calculation ability subconsciously for Reflection. It is set to reflect any vector that comes in contact with him, with the exception of Air, gravity, and others necessary for his survival. If anything he has not set to come through touches him, whether he knows it is coming or not, it is reflected. About magic, it works similar to Kakine's Dark Matter, in that it uses vectors from outside of his known reality and so bypasses Reflection. However, once he gets a grasp of the alternate physics involved, he can set them to be reflected. Finally, with regards to Teleportation, it involves calculating motion into other dimensions, the 11th precisely, and back. The key word being motion, in that moving something between dimensions requires at least to vectors. As long as he understands the physics, and givin' the fact of his superior calculation and probable previous encounters with Teleporters, not an uncommon power so I am inclined to believe he does, then reflection will work.
The most probable result would be either the teleported item reappearing in the wrong location, or not returning from the 11th dimension at all.

Now with that cleared up, you can come up with a way way to defeat Accelerator without Imagine Breaker. After all, different styles of magic, like Jewish as compared to Roman Catholic, have different innate vectors.