Amlogic should auto-detect HDMI vs CVBS output and configure itself as required. I've never tested it (as I have nothing that takes composite input) but the DRM driver supports it.
Ok. The auto detect wasn't working last year- I had to go create /storage/.kodi/userdata/disp_cap and enter cvbs576 and cvbs480 for AV display (and then remove the file for HDMI display.)
Is auto-detect a more recent feature?