JSON data for any particular instance may be stored in the base table row or in a LOB subtable. Use FNC_GetJSONResultLob only when the JSON data will be stored as a LOB. If FNC_GetJSONInfo or FNC_GetExtendedJSONInfo returns numLobs > 0, you can use FNC_GetJSONResultLob; otherwise, you should use FNC_SetInternalValue instead.
You can use FNC_GetJSONResultLob to set both character and binary JSON data.