I don't want to be unnecessarily disrespectful but this discussion has metastasized way out of proportion.
Anyone can mine 100kB OP_RETIRN currently. Spammers are mining 4MB jpegs in witness data with witness discount.
Apart from Luke's convoluted logic on "misinterpretation of data" there is no difference between csam in OP_RETURN or OP_FALSE (ordinals).