There is no exact rule that I know of to pre-set for a particular day's sailing. You rake back for higher wind to keep the bows up so they don't submarine and you don't pitch pole. Because the more wind, the more the bows get pushed or driven down. Rake back too much, the bows are too high up out of the water and won't grip enough to tack quickly.
IMO, it is a matter of the balance that you like best after experimenting. Having the adjuster at the five hole is probably a good average place to start. Hopefully, others will chime in with some advice too...
Conventional wisdom amognst racers is that you rake back until you can't fully tighten the mainsheet, and then go forward a hole or two. With a Hobie brand sail and a ten hole adjuster, I think you would be in the 9th or 10 hole.
At the same time, most of us have the shrouds very loose. This allows the sail to go farther forward downwind.
I personally have been experimenting with a little less rake, but can't seem to make up my mind what is best.
Experienced sailors don't have any trouble tacking with the rake fully back. However, you have to hit it exactly right every time. As JJ says, forward helps tacking.