Ludwig 'Louis' Seecamp joined the German Army around WW1 as a young man and was trained as a master gunsmith there, he would serve again in WW2.

He had an encounter there with a Russian soldier, just the two of them having to draw their sidearms, and so they did, almost simultaneously. The Russian soldier drew and fired his Tokarev pistol, striking Louis in the cheek, and Louis drew and fired his Walther P38, hitting the Russian soldier in the chest, killing him on the spot.
The shot Louis received took a gash out of his cheek and removed some of his teeth, but him being able to draw and fire his P38 so quickly had saved his life, shooting the enemy before he could be shot again, and he attributed that to the speed afforded to him by the DA trigger. This near-death experience is what made him regard DA/SA as the perfect pistol trigger.

Going to civilian gunsmithing after the war, he made it over to America, and he became VERY fond of the 1911 pistol, he thought it was almost perfect, but to make the 1911 a truly perfect pistol, it should have a DA/SA trigger, just like a P38 did, thus he designed a conversion to make that a reality.
It's almost a bit of a hack, but it does work. Here's a .45 Commander with the Seecamp conversion.