MBI5026 led driver datasheet question
When Latch Enable (LE) is high, the data in the shift register will immediately appear on the LEDs. So, you don't want it high while you are loading the shift register or the LEDs might flicker.
#1 is better than #2, but I would do it this way.
Start with LE low. Load the shift register, then set LE high momentarily. Keep it low until after you have loaded data again.