I tried number of things to make my Les Paul less muddy and boomy in the neck possiton for a very long time.
After couple of pickup swaps, I figured out that i need a pickup with alnico 2 on the neck, rather low impedance becouse I got 4 gain stages on my pedalboard.
This pickups sound fantastic, not to bassy on the neck, neither to bright on the bridge possition.
Only issue is that you have to use crews that comes with the pickups, and there is a limit of height on the bridge pickup. It makes it harder to balance volume between them.