Your memory serves you badly, a background check is required for a Non-OA (which is for retirement) , not a Non-O for marriage
Also, of course there is a marriage visa, what do you think the Non-O based on marriage is?
Also, also, you do not extend your Non-O based on marriage, that is done and dusted, you extend your permission of stay based on being married to a Thai national.
Apart from that, well done 🙂