Power Disc Brakes not working on hard stop?

OP
Another new thread picture makes me want to ask if there could be any kind of interference with that gizmo that bolts on.
Seems to me, years ago, someone required a notch or somesort to clear the firewall, or linkage binding on something.
Just really scrutinize the linkage that appears to be hard to see.
Just throwing spaghetti. .