Shifting the burden again. There were TWO viable options that did NOT require those two drastic turns. Your beloved WC claimed in 1964 that the turns were needed, but like almost all their claims they failed to support it.
It is apparent that you cannot support their claim either.
The crux of your notion of a superior route down Elm is that the limousine would have traveled faster through Dealey Plaza. Therefore, you have to show that the only limit to the speed of the limo was the two turns. You have yet to do so. Furthermore, you assume that the primary, if not sole, criteria for route selection was to facilitate the speed of the limo. You have yet to substantiate that as well.
I'll note in passing that Alvarez plotted the speed of the limousine in "A Physicist Examines the Zapruder Film" and found that it runs at a constant speed of about 12 mph between frame 160 and the beginning of the deceleration that begins just before the last shot. If the last turn unduly slowed the limousine, then there'd be marked acceleration as Greer strove to get the car up to speed.