I finished placing and routing the LEDs, one each 3.4mm (not minimal but required to ease soldering).
We have less space and MOSFETs are going to take more space than I originally thought. Although, if we use less MOSFETs, it should be fine.
Still, we won’t have much free space at the top of the panel for the LED drivers. Since they are quite small, I think we can put them on the two sides.
Here is the updated routing idea: