Loving my Foil Glide 7.0, today had 10-15 knots instead of usual 5-10, so tried the lower outhaul for first time. Sail looked much better along the leech, and was more powerful, and easier to control.

Forgive me for asking a dumb question, when I used to windsurf in the late 80's, sails only had one outhaul point, now all the sails have two, under what conditions do you use the upper vs the lower?

Light wind upper and higher wind lower to allow more twist off

I like sail all conditions in the position i prefer and that depends on what sail i have on

This is my take on it others might know more

yes as above ^
but also depends on how tall you are.

I'm 1.83 and use the top hole with slalom sails and on my glides (5.0&7.0)

Top hole 99% of the time for me, but it sure is handy being able to switch to the bottom hole when i get caught out over rigged.

If you are too lazy to change the boom settings on the water you can move your clew rope further up or down to change boom length.

The bottom hole opens the sail up a bit when very overpowered.