Before revision:  Iterative refinement for MAPF is desirable for three reasons: 1)  optimization is intractable, 2)  sub-optimal solutions can be obtained instantly, and 3)  it is anytime planning, desired in online scenarios where time for deliberation is limited.
After revision:  Iterative refinement for MAPF is desirable for three reasons: 1) optimization is intractable, 2) sub-optimal solutions can be obtained instantly, and 3) ~ it is anytime planning, desired in online scenarios where time for deliberation is limited.