For this purpose I have been trying to adapt snippets from the Macro_sequencies.lua (auto start) file, so far with no joy. Action lines take this form:
push_start_command(dt, {device = devices.AMPCD, action = AMPCD_commands.AMPCD_off_brightness, value = 0.85})
I think the key is some editing of the functions and variables at the start of the script, but I have been unable to figure it out. If we can get this script to work, then invoke it with a do script trigger. Edited Macro-sequencies scripts do work in multi-player environment.