In addition to the question of rear license plate visibility, here's another factor to consider: Would the tail (brake AND turn signal) lights be very visible to vehicles behind you? I notice in your photo that this is not the case at all for the right turn signal on the minivan.
If the dirt bike does stick out past the edges of the RAV4, keep in mind that what sticks out will catch air, and the additional drag will put more force (torque) on the hitch receiver.
I don't think it's a question of the V6 RAV "can't" do it, because until it's tried one wouldn't know for certain. I think it's more a case of "shouldn't" do it because it's pushing the safety limits, in several areas, and probably violating the law in some cases such as visibility of the rear license plate and turn signals.
If one were to try it, I think this is a case where the (more expensive) Toyota OEM hitch would be highly advisable, provided the RAV4 has the Tow Prep package. This is because the OEM hitch attaches to "dog biscuit" brackets (seen at the top of the first image) that hang down from the "frame" with the Tow Prep package, providing more vertical support and probably reducing the amount of "twist" that can be incurred on the "frame." Less expensive OEM hitches do not leverage these additional support points:
Here's part of the OEM hitch, with "dog biscuit" attachment bracket at the bottom of this picture:
If one were to try it, one would think adding air bags to the rear suspension would be highly desirable as well, to help keep your headlights pointed to where they should be.
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