These "tests" miss the point.
Under no operational and technical circumstances should above-idle engine thrust be available / selectable to cockpit crew when the reverse selection has been made and the reversers are not in the fully deployed position.
What have I missed in the intent of these tests? For me, this smells of finding ways to blame the crew for the overrun. I don't know the actual operation of how reverse is selected in this aircraft, but is there any news regarding fixing the system that permitted above-idle thrust with reversers stowed while reverse was being called for by the pilot?
Lots of what ifs have to be considered when designing systems. Redundancy is the key to descision making. One of the major tenants is to err on the side of full takeoff thrust available should the pilot elect that action. If this is not what is wanted the pilot always has the ability to pull the cock on the engines and use the brakes. Even in a confused state this should be an inherent feature available.
OTOH as a logical state it's preferrable that full forward thrust to reject a landing can be quickly obtained.(spool up times start the clock)
Given the possibilities for short times for decision making it seem the pilot has more time to make a stop decision than to make a go decsiion.
IMO This crew just didn't sort this decision out in a reasonable time.
I wouldn't want to redesign the system to furthur reduce the time to make a "Go" decsion by putting in yet another interlock.