To me it's timing. Majority of the time the headsail will tack across the staysail stay fine. It's all about timing when you come about with how much and when you release the jib
sheet. Practice, you'll get it. Use sheets
without a big knot
at the clew also.
Basically, just as the headsail starts to backwind a bit, you release the sheet just enough so it fills between the stays, the power
of the wind
is then in that concave "bucket" , then release and it pulls the sail right through.