the A-8/R11 is actually a A-8/N
the N stands for Neptun and in the case of the wonderful profile the Neptun FuG 218 radar which was only fitted on a scant few machines in 1./NJGr 10
yes the Gr in this case stands from gruppe which had 3 staffels. NJGr 10 had single eninge jobs in the 1st and twin engine in the 2nd and 3rd staffels
NJGr would be a night fighter gruppe and NJGr 10 tested new equipment and radar devices. the first staffel for part of it's operations flew anti-mossie ops in the Fw 190 A-6,7, and A-8 and then accepted 109G-6/AS, later G-14/AS and then finally G-10's into it's ranks.
JGr - jagdgeschwader gruppe with the same reasoning behind it. a test unit for new a/c and weapons.
there was a JGr 10, JGr 25 and 50 and the last two had the r removed for propaganda reasons to show the Allies they were supposed full on Jagdgeschwaders. JGr 10 tested different rockets ( air to air) throughout it's career.
E ~