BrainModular

I want to use the SetVst Params script to control VST's patched on another line in the grid. Is this possible or can it only work in the patch the script is in? I really don't understand how ('SET_TARGET_PATCH','SENDER_PATCH'); can be used to select another patch.

you can access the current patch, a sub patch or parent patch, afaik not a different patch on different line if using grid mode.
but you can use a bus to send the txt message iml command to another patch anywhere in wksp that will execute the command locally,
either via script or using the sendMsg module wich has a 'lines' input. in your case that mean you should add a txt output out of the script instead of it acting directly wirelessly to iml. that txt out go to a bus, get it back in concerned patch that trig iml to set the vst 'locally'.