I'm all in favour of safety and innovation (Thinks - did I really need to say that), but what we have at the moment is a situation where every certified commercial aircraft has one or more anti-collision beacons at prominent location(s) on the fuselage/empennage. Everyone, globally, who works airside in any capacity knows that if they are flashing then the aircraft is live, the engines could be running, and the aircraft can be expected to self-manoeuvre and to operate external control surfaces without further warning. If they don't know that then they are not properly trained or supervised, and additional lights are unlikely to change that. This situation has existed for decades. The only airframe I ever had trouble with was the Dash-8 which (in my experience) only had a fin-top beacon.
Just off the top of my head, aircraft currently operating with engine intakes at pedestrian level include all generations of 737, 747, 757, 767, 777, 787, A300 series, A319/20/21, C series (by whatever name), Avro (by whatever name) E-170 (etc), CRJ-Series ........
Manufacturers of such aircraft include Boeing, Airbus, Bombardier, Embraer, Sukhoi, Mitsubishi, Antonov ........
National Airworthiness Agencies with primary responsibility for certifying these types include USA, UK, EASA, Brazil, Japan, Canada, Ukraine, Russia (yes Russia) ..........
And their military Airworthiness Agencies.
This proposal is only going to be worth spit if it is adopted universally, otherwise a complacency may arise that no nacelle-beacon means "safe". So all we have to do is to get all those manufacturers to agree a system of lighting, have it approved by their Airworthiness Agencies, and have all the customer airlines agree an implementation process (to including legacy airframes). And this thread is only looking at an engine incident; what about the hazard from an errant flap or aileron?