OI's I leave as is. So I dont use them.
I don't see the point in using set OI's as opponent changes every time.
And I dont use them per match either. Last 3 years of FM, I havent used any OI's ever.
I don't know if the creator of the tactic uses any.
While I have the odd poor result, or the usual games where I'll generate 30 shots to 3 and lost 1-0, I generally go into most games confident of a win. This tactic generates plenty of chances and is pretty solid at the back.
One thing I did tweak ever so slightly was getting my players to cross the ball more - one thing I've noticed about all tactics is that players are running inside the box and shooting from some ridiculous angles where they have no chance of scoring, outside of a bad keeping error. While this tweak hasn't eliminated this aspect completely, I'm finding that they will centre the ball a little more or get in a few more crosses than they used to.
Either way, this has been a pretty strong tactic for me so far and one that can fit most teams, no matter what league you're in.