A simple experiment can be conducted to testify if the time alignment affects anything audible. Take a pair of speakers that you think have a good image, tilt the front panel back and take a serious listening again to see if the imaging gets thrown off. Conduct the blind test with the help from the 2nd person if necessary to eliminate any gussing game or mental effect. To me, I need to admit I could not hear any difference. However, at the same toeing angle, tilting them back does change the soundstage slightly.
