Any reason not to take advantage of extended hours (sell orders) and 24 hours (buy orders)?

I believe a stock like FedEx will perform well in the near future. But in the very near future I see it dipping about 10%. I went to place a limit order on Robinhood and was surprised it let me select 24 hours for the limit order. It feels weird that there is even an option to still only do "market hours" or "extended hours" when you can simply click the 3rd option of 24 hours. Why wouldn't everyone do this with limit orders? What advantage, if there is one, would there be to only having the order be fillable during market hours or extended hours? Same sort of question for sell orders except there is no 24 hour market option for sell orders. Instead you can select market hours or extended hours. Same thing: Why limit yourself to the more intrusive option when you can buy during extended hours?