See post 13, please. If this is terrorism (and I’m certainly not ruling it out!) this isn’t garden variety terrorism. Can pretty much rule out the classic bomb in luggage/shoes/underwear/can of soda. ACARS was phoning home, in realtime, events that happened to that plane.
This is Whalid Shoebat’s take. He’s ex-Muslim ex-PLO I believe.
Everything You Need To Know About The Muslim Kamikaze EgyptAir’s Flight 804 Pilot And Why He Drowned The Plane In The Sea
I think an incendiary device in the cockpit could meet all of the forensic comparisons based on what we know today. A non-metallic bundle of road flares, for example. Either in the forward cockpit lav or in the cockpit itself.