do you know where I can gain a copy of one of the original MCU scripts? I want to see if any modified scripts have removed any important features around device placement.
Each DAW has their own scripts. I can send the Studio One script for the MCU if you like (javascript) but it won't help you with placement. Studio One handles that internally so there's nothing in the scripts to do with placement. S1 just presents each controller with the correct tracks, having already worked out the relative placement and how many channels it has. The placement is setup within Studio One itself.
I'm really interested in device identity, a way for the script to call what device it is and where its place as per the x1, x2 and so on, the goal is any order of units can be placed by a user without editing a script
I've no idea how you would do that in FL Studio as I don't know how the FL scripting works. Do you have a separate script for each extender unit and the channel offsets are hard-coded in each script?
If you don't want users to edit the scripts, you could consider having a settings file (assuming FL scripts are allowed to read files). I have one for my script for setting user preferences. Users could edit that file and specify the order the units are placed on the desk. The individual scripts could use that information to know where it is and work out which tracks it should be dealing with.
If you only have one script that's used for all the extenders then you'll need a way to identify the device you're talking to. Can the script get the Midi port name for example?
Paul