[josephcsible]

Put physical dividers in the overhead bins so that oversize luggage won't fit at all and has to be gate-checked.

[_tqr3]

The main disadvantages are that physical dividers add weight and require maintenance. Also, they reduce flexibility, preventing the ability to tetris more bags into a bin.

[josephcsible]

Sure, but I suspect that the savings in reduced turnaround times could be enough to offset those things.