This inspired me, but I don't think I did the same thing you've described. I like using the track, though, and 5mm is perfect. I basically made long soft shackles with a couple 12mm nylon spacers to hold them in the track, with a few modifications to allow for a couple extra attachments.

Don't know the infusion, but for all boats I sailed so far:
If the nose dives (by then you did make already an error, right? But some errors are not avoidable) push the tiller *hard* to
a) turn the nose into the wind and reduce the angle of attack of the sail's
b) pull the stern down/ nose up (if you have sufficient heel angle)
In some cases you have to drop the main too.

The trick is to use sufficient rudder

Cheers,

Klaus