There's another similar thing needing correction, which is that the LEDs near the center sweep a much smaller volume than the ones at the edge, and should be dimmed in order to yield equivalent luminance. LEDs describing tiny circles very close to the center would need to be dimmed a lot since they'd essentially be stationary. Wouldn't it be better then to sweep slightly larger circles at the middle anyways?

If we're going there, note also that all the LEDs not on the edge are blocked by other LEDs (or the board) part of the time; LEDs on the edge are visible even past 90°.