@mpl Wow, man, you're a legend! Thanks so much for your attention to this! I'm getting this error: "...used FX TCP controls to instances in selected tracks.lua:12: attempt to index a nil value"
I'm selecting all tracks, then floating the plugin with the Fx Parameters I wish to apply to the other instances, then running your script. Is it because my param names all have Aliases, or because my set of aliased params are loaded from an Fx Chain? It works only with Fx I have loaded from the browser and then doesn't preserve param Alias. I hope I'm not asking too much here... I can upload a project file with my fx chain loaded if that helps. Thanks again!