SU1946 stands for Simple Universe 1946, it is a series of late-WWII (or prototypes) planes plus some fiction. Planes in this series would have significantly better performance than their historical counterpart, and would receive a "Z" in their names to distinguish them from other, more accurate replicas.

In real life, the Messerschmitt P.1090 was used at least for two different designs, one was a project related to the famous (well, more famous than this) Dornier Do. 335 "Pfeil", and the other is a "modular aircraft" concept that only sees one drawing surviving to this day (and even that single drawing is suspected to be fake).

The aim for the P.1090 was to build a versatile aircraft with modular design, By installing different modules, the aircraft is expected to take a very wide range of roles, including: fighters, night fighters, strike fighters, fast bombers, recon aircraft, attack aircraft, high-altitude interceptor and so on. The aircraft comes with jet engines or propeller engines (inner wing module), different weapon loadouts (lower nose module, mid section module for bomb bays or extra fuel), different wing areas (3 kinds of outer wing modules to choose from), as well as different avionics (rear hull module).

In our Simple Universe story, this was the answer Messerschmitt came up for the heavily worn-out Chinese battlefield. A simple, versatile and cheap modular multirole aircraft. Unfortunately, the modular nature also made it easier to be trafficked, and the Nationalists soon found themselves fighting against the exact same design from their Communist opponents.

Performance:
Varies according to modules installed, but generally takes 5 seconds to turn 360 and has a top speed of about 1950km/h at sea level.

Please take off with 30% power and press the pitch a bit unless using one of the experimental booster modules.

Modules not installed on the plane(from front to rear, left to right):
Drop tanks x2
31 m2 outer wing set
36 m2 outer wing set with R4M airburst rockets (for enemies head-on you should fire AG6 at about 4 km, depending on your speed and the target's).
Heavy fighter tail section with radio detector (Trim to rotate)
Experimental upper engine module (AG7 to engage, fits on the front pylon of the experimental carrier tail module)
Experimental takeoff booster (RATO) (AG3 to engage, AG4 to discard and open chute, front pylon too)
Refueling pod (same as the one on my Me 262 HGIII, trim for extend/retract refueling drogue, AG5 for magnet, fits on the rear pylon of the experimental carrier module)
Experimental Carrier Tail Module (in orange), used to carry the experimental modules. When carrying this, please paint the nose and wingtips in orange.

Modules already installed:
Single pilot, nosewheel nose module w/ 4x MG213 revolver cannons (70 damage, 1050 m/s, 1200 rpm)
Gun pod with 2x MK213 30mm revolver cannons (same as those from HGIII)
bomb bay with 3 pylons (NOT DESIGNED TO BE FLOWN WITH BOTH GUN POD AND PYLONS ATTACHED)
"normal" tail module

Activation groups:
AG1: Drag chute
AG2: Tail hook
AG3: RATO booster on/off
AG4: Jettison all experimental modules/RATO chute
AG5: Magnet for refueling drogue
AG6: R4M rocket salvo
AG7: experimental top engine on/off

Trim: Radio detector/refueling drogue extend and retract.

Suggested configuration:
1. Fighter: 36 m2 wings + 30mm gun pod + normal tail.
2. Heavy fighter: 31 m2 wings or 36 m2 wings w/ R4M + 30mm gun pod + radio detector tail.
3. Strike fighter: 31 m2 wings or 36 m2 wings w/ R4M + bomb bay + normal tail.
4. Experimental aircraft: 36 m2 wings + nothing under the belly + experimental carrier tail + any of the experimental modules.

This aircraft has the best agility in the whole SU1946 series, and even an AI can shoot down a human-piloted Me 262 Z HGIII with the fighter configuration if they survive the first few seconds of acceleration without spinning. An HGIII would have to boom and zoom if it wants to stand any chance against the 1090Z.

Mods used: 20mm Hispano autocannon, fine tuning, overload.