Can anyone tell me if the Downloadable Backup files of X4 Community of Planets Edition Downloads into
one single install file that includes all of the DLC ready installed...?

OR is the base game and DLCs all separate install files ? like the original X4 is ?

Without owning the bundle my wild guess is similar way as original X4 Collector's edition that included base game + DLC downloads separately.

I just purchased the X4: Community of Planets Edition and got:

setup_x4_foundations_7.10_hotfix_3_(64bit)_(76716).exe
setup_x4_cradle_of_humanity_7.10_hotfix_3_(64bit)_(76716).exe
setup_x4_kingdom_end_7.10_hotfix_3_(64bit)_(76716).exe
setup_x4_split_vendetta_7.10_hotfix_3_(64bit)_(76716).exe
setup_x4_tides_of_avarice_7.10_hotfix_3_(64bit)_(76716).exe
setup_x4_timelines_7.10_hotfix_3_(64bit)_(76716).exe

and accompanying *.bin files

so it comes as a base game with all DLCs as separate install files.