Depending on environment luminosity (which might change due to sun, clouds, …) adapt the output brightness from the ppm.
This would improve user experience and battery duration (compared with full power in presentation mode) because of optimal brightness. It’s like mobile phones with adaptative brightness.
As an advanced setting would be to set Max and min brightness from ppm depending on outside high light / low light conditions. Or simpler one. If low lightning switch to eco else normal or presentation (full power) mode.