You can only use EQ to optimize a single listening position fully. If you use a "room correction" program taking multiple measurements for more than the main listening position, it will unavoidably make compromises to suit all those positions. As it isn't possible to use one set of EQ adjustments to fully suit multiple listening positions should make it obvious that it is a 2-dimensional tool.
Even if we are talking about first reflection points, it's not that hard to install room treatments for multiple seats, as you can probably put up more absorption panels to cover the reflection points for all the seat positions, as the ones you measured for ART.
But room acoustic treatment isn't just about controlling first reflection points, and in many cases, even more about taking control of the time domain and evening out the decay times in the room, and that will have a positive effect in every listening position in the room, making it a 3-dimensional solution.