even though strictly speaking by the alteration of the approach ban definition a few years ago
Am I missing something; having been out of the game for a few years? Is there more to approach bans than just RVR/VIS?
a cloud base well below the MDA.... I could shoot the approach (even though I know that cloud base will prevent me from seeing anything ) and not care of the outcome
I hope you always care about the outcome, but I suspect that was a throw-away line. I would also expect your company to want you to make the approach, if it's legal. The airmanship considerations are your own. Cloud base could be BKN, and remember my comment about terrain under the approach affecting the cloud. Give it a go, be prepared, and have a plan B to hand: as always.