What's recorded in the orange box may not include 100% of what's displayed on the pilots' screens
Really? Do you have any evidence of that?
What is recorded in an EFIS system is the output from the display management computers. What goes to the screens goes to the FDR.
The questions nobody seems to be asking is, will it improve flight safety or simply make life a little easier for investigators? Have the installation of CVRs prevented any accidents? Will the installation of video prevent any? Prevention is the supposed purpose of these devices.
What will be next? Caps with electrodes so brain activity can be recorded?