Creating faux master intensity for RGB fixture

I have an LED bar that has individual pixel control of each 8 LED sections. When running in full pixel control, it only offers RGB control per LED, no master intensity, strobe, anything. So RGB x 8. When building the fixture I just made it 3 channels and patched is 8 times. Is there any way to make it so there is "faux" intensity? Ex- When I pull the master fader down, I would like them to go off - Another, I would like to be able to do intensity effects on the fixture mixed with a group of other fixtures, last example would be to have like a submaster to control their intensity. If there is no one to create this faux channel, any work arounds like using a macro command or changing it to like CMY/RGB/HSI type fixture setting?

I plan on using this with the Plot Mode and Pixel map layer, which has kind of acted as a type of an intensity if it is running a plot with pixel map layer on it. It was my attempt, but got pretty clunky.