Perfect frequency response from both sides sounds like it would be super important but in practicality for what most people describe as imaging it is not. Symmetrical installation in general is far more important.
What most people describe as imaging is not exact placement, which has no meaning at all really. If I have a left / right volume difference and something shifts 6" to the left or right, that is not going to be critical.
What most describe as imaging is an ability to visualize an exact spot for the sound source, not just "over there" though a lot of people like "over there". A well designed cross-over is going to provide, given suitable speaker/listener distance time coincident wavefront and certainly with digital cross-overs, it is very easy.
What most people describe as imaging is not exact placement, which has no meaning at all really. If I have a left / right volume difference and something shifts 6" to the left or right, that is not going to be critical.
What most describe as imaging is an ability to visualize an exact spot for the sound source, not just "over there" though a lot of people like "over there". A well designed cross-over is going to provide, given suitable speaker/listener distance time coincident wavefront and certainly with digital cross-overs, it is very easy.