What is the Tow Vehicle (TV)? I can engineer you up a sliding tongue system, I think it is a great idea. Put an open Kammback "receiver" fairing on the TV and pull the trailer up into it.
Couple the mechanism to the TV's Vehicle Speed Sensor (VSS), so it will automatically move as you indicated, but progressively. Reality is you will not see more than a couple of degrees deflection above 25 MPH, so engineer for that. If you want to be sure, build a test jig and go driving and you'll see.
I'd design it so it will work automatically, but will be easy to override manually in case of a malfunction. I'd install a pair of sensor bars to let you know before you start bending things.
It combines a couple of very easy things, since the trailer can now have simpler front.
Open Kammback is also simple.
Why are all the cool projects clear across the country?
__________________
2007 Dodge Ram 3500 SRW 4x4 with 6MT
2003 TDI Beetle
2002 TDI Beetle
currently parked - 1996 Dodge 2500 Cummins Turbodiesel
Custom cab, auto, 3.55 gears