Not quite sure of the syntax in your nod example
Do you want to start the :D4 after 0.25 start the :Ds5 and to sleep 0.25 from the START of the :D4?
In previous midi conversions I have split overlaps like this into separate parts and effectively played them in separate live loops. The technique you have used in for edample the :LL1 loop further up this thread has allowed you to have notes of different lengths sounded together in the same live loop. I guess the nod command is to try and do this too more simply.
