I remeber reading in another thread that somehow it may be possible to
run a max patch parallel to mapd that could light LEDs on a monome by
adding two ports to a map. (Im trying to light LEDs with midi messsages
from Ableton).

I cannot find find anymore information about this. Has any one
succesfully done this?

this is presently not possible, as mapd doesn't accept input (via OSC), 
and you can't share the serial port between apps.