using [udpsend] with multiple data streams

Hi, I have a max msp patch which works (pasted below), that I would like to use with M4L.

The main patch receives data coming in from 12 sensors via the Arduino. [zl slice] separates the data into 12 patchers, which each contain an audio file that is manipulated using the incoming data.

The issues I'm having with transposing this to M4L are:

1) I'm creating a M4L device (a copy and paste of the max patchers) in each of 12 Ableton tracks to receive the data and manipulate the audio. I'm using [udpsend] to take data from each [zl slice] in the main patch and [udpreceive] to receive it in the M4L devices. I understand there is a way to use "---" which allocates a unique identifying number to each [udpsend] (without it, each [udpreceive] is receiving data from all of the sensors). But I'm unclear exactly how to do this...(have read the files/searched the forum/experimented with it - still unclear).

2) Alternatively, If I put the [udpsend] to receive directly from [fromsymbol] in the max msp patch, the data stream goes to [udpreceive] in M4L and shows in a message box, but [zl slice] from [udpreceive] doesn't work?

3) Is there any advantage/disadvantage to putting the main max patch in a M4L device (in it's own track in Ableton?), so I am only using M4L and Ableton, and not max msp as well.

Thanks