Beauregard
Point taken re: 'who flung dung'. I believe I have a record of being civil and erudite on public forums, but I do respond in kind when attacked or abused. Cyber bullies are no different than the school yard variety.
Having recently blown up your gun, I can understand your apprehension about duplexing or any other reloading practice that takes you out of your comfort zone. Good - that fear will keep you safe.
How much more evidence do you require that duplexing "significantly improves performance without sacrificing safety"? My experience, that of others and references such as I quoted from "The Breech-Loading Single-Shot Rifle" by Major Ned Roberts and Ken Waters are obviously not impressing you.
If long strings of duplex loads without adverse effects on rifle, brass or shooter, great accuracy and minimal barrel fouling don't convince you, what will it take? Do not construe this an attempt to convert you to duplexing against your better will and judgement. A man's gut is one thing in life that will not lie to him. I trust my gut feelings implicitly, and I don't go where it tells me not to.
You could contact Steve Garbe at Black Powder Cartridge News for his views on the topic. He knows whereof he speaks and does so with 'been-there-done-that' authority.
As for it being an unnecessary complication, it is just one more step in an already complicated process. I first charge cases with the smokeless, block check and then charge with drop tubed BP and compress. Since I am using my 'lectronic Lyman DPS III powder dispenser for the BP, I have sufficient time between charges to drop the smokeless charge, but I feel safer not doing so.
That's me listening to my gut feeling .... ;>)