"Activity" sensor: "display off" shouldn't mean the Mac is inactive

[Stooovie]

Is your feature request related to a problem? Please describe.
The problem: as of build 2021.55, the "Activity" sensor is reported as "inactive" (or "off") while the display is sleeping. That seems odd as the computer is very much active - for example, it's doing rendering with display off.

Describe the solution you'd like
Either let me specify what constitutes "inactive" state of the computer, or provide additional "Cpu usage" sensor. As of now, I have no way of actually telling if the computer is doing work.

Additional context
"Frontmost app" sensor helps but it still doesn't tell me if, for example, the frontmost app hasn't crashed. I would love to be able to, say, set an automation that would make a light red while the CPU is heavily used (=rendering) and green when the work is done (CPU usage is low, not rendering).