i look i books to find some Info :
Me 328 start as Me P.1079 in July 1941 by Dipl.-Ing. Felix Kracht
Idea was a Fighter or Bomber in Mistel configuration
Bomber
as Mistel configuration with 1000 kg Bomb (later 1400 kg) and no Engine
the carrier plan makes a Stuka attack and drop glide Bomber.
later the Me 328 design was add 2 x V-1 Argusrohren Engine.
because they cheaper as piston or Jet Engine
Bordjäger (Parasite Fighter)
one Me 328 A (with 2 or 4 Argusrohren) on top of He-177 A-5 or Me 264 Bomber (Mistel configuration)
major problem only fuel for 30 minute flight but the Me 328 can be Refuel by docking on His Bomber!
this version has extendable wing as variable wing geomtry
2 x MG 151/200 with 200 bullets
Schnellkampf Flugzeug (fast Interceptor)
same as above but the Mistel carrier bring Me 328 A, 150 km range to Target.
even as Aircraft for Submarines !
German U-boat carry in container a Me 328A (like Regulus Sub)
the idea was drop, until beginn 1943 the SS take back up
as "Selbstopferung" SO-Flugzeug (German Kamikaze)
Me 328 B cheap disposable, one way Aircraft with 2400 kg Explosive
no extendable wing.
Source:
Geheimprojekte der DFS (german Language)
Horst Lommel
Motorbuch verlag ISBN 3-613-02072-6