thank you
Yes i realized that I had a different setup from the original design. though the forestay in the jib I got proved to be too weak: I went for the annual Tanzacat race (from Dar Es salaam to Zanzibar 5o miles in the indian ocean) met 2 mt waves and after a couple of hours the mast was right in the water because the thimble at the foot of the wire failed. Jib is new.
Also I keep the getaway at a club ready to go to the water. I would not even think to step up and down the mast each time (3 times per week) and the jib cover I see is recommended for only short time especially in very hot and humid weather condition.
From your answer I thought that if I put a cleat just after the hoisting block hence reducing the length(to about 10 inches) of the jib halyard that may elongate under tension replicating the same fork trick of the main halyard I may be fine. The main halyard though is left with only 5 inches after it is trapped in the fork. (By the way my used Getaway main halyard misses the rope + chain original setup. All it took was a knot at the right length in the halyard that it trapped in the fork on top of the mast. This has proven to be sufficient for eliminating the problem of the main coming down when under tension

)
Another idea would be to open the luff pocket, remove the existing wire, sew a 1 inch velcro all along the luff pocket that would be closed around the much stronger original forestay while hoisting the jib. Would the velcro be powerful enough to keep the pocket closed under tension ?
What do you think ?
Thank you