Fact is that A-11 and A-12 pup up after the War
in US Military documentation about German Rocket technology, based on interviews of Von Braun made during first interrogation by US officer in Garmisch-Partenkirchen, Bavaria.
Later he made some study during his imprisonment (1945-49) in Fort Bliss, Texas USA.
From there they made V2 test flight at near by White Sands Missile Range in New Mexico.
Acutely how far were the Von Braun "Aggregate" at end of War ?
He worked on A4b a winged V2 for longer range, two test flight with not much success until January 1945
Design he worked on A9 a enlarged winged A4 with 30% more thrust, the A4b were aerodynamic test for A9
A8 that were Storable fuel- Pressure feed version of A4
That rocket team ended up in France after the War, there made design work on the "Super V-2" after it cancellation, they worked on French Veronique the Grandmother of French Rockets...
A10/A9 was seems not Von Braun Idea, but attribute to Ludwig Roth und Graupe, depending the Source material.
there some indication that SS were building a Rocket Production site, south of Mittelwerk what could be for A10/A9, but the Plans are lost so we never know for certain.
A11/10/A9 depending the Source material.
Von Braun talked already about it in 1945 during first interrogation by US officer in Garmisch-Partenkirchen.
but since the Official documents about A11 are USA origin and there no german ww2 documents available (lost in US or Russian archive ?!)
for moment the A11 is highly speculative brain child of Von Braun
this A-11 picture is made in USA
not in Germany !