Getting composite video on RPi4 is currenntly a bit messy as composite has to be expicitly enabled in the kms driver, too (on RPi0-3 it's enabled by default in kms and there's an option to disable it).
This means you either have to modify distroconfig.txt (which isn't great as it will be replaced on every upgrade) or copy the contents of distroconfig.txt to config.txt and disable the distroconfig.txt include (which isn't great either as you may miss important changes to distroconfig.txt on upgrades).
That being said you need to make 3 changes to get composite out on LE 10.0.1:
add "composite=1" to the kms dtoverlay in distroconfig.txt
dtoverlay=vc4-kms-v3d,cma-512,composite=1
enable tvout in config.txt
set your desired mode in cmdline.txt (on the same line after "quiet"). eg for PAL:
video=Composite-1:720x576@50ie
or for NTSC:
video=Composite-1:720x480@60ie
Note the "e" at the end, it's important, if you omit this kodi won't detect the output (as connector status is "unknown" because composite doesn't have hotplug detect, with "e" in the mode it's forced to "on").
so long,
Hias