just whack in overly rich figures for hat area, that's stop him wanting to pour fuel down the exhaust lol!
if it is to be done, it needs to be done right, but if you're fitting this around other work and for free you'll find you'll work on the map in stages, just driving around smoothly can be a big enough job, mines still a bit of a pig below 1500rpm off throttle, just rarely on that bit of the map to sort it out in a hurry.