Ive got broken ankle from kiting 3y ago, broken collar bone from bad jump too, 7y ago. Plus heaps more. So I should not use a strap?
Started jumping with a foil this season.
But, everyone is different. I would strongly suggest to relax. Nothing will happen. Straps are fine. One knows how to kick off the board, if we can do a board-off, this is easy too. Sure, straps should be slack. And flexy. Can be anything, releax, everything works just fine, can be a rope or a webbing. It justs works.
However, you WILL bounce your board on the hook. And hook might crack the board on many places. Infact, it might make a complete hole in it. Yep, it happened to many.
Sliding rope is a no go when learning, imo.
Why? Because you will fight the board. Hence, smaller board, easier to fight and hook is in the same position all the time. Add a slider and everything changes to worse.
The foil just wants to go upwind. It has its own mind
So, a TT style build board is easier to grab. Again, you will fight the board which will turn many many times into any direction. This is why Moses 633 helps heaps, because it floats. So no need to fight it when water starting, since the mast is in position to start.
Other, non floating wings and masts sink. So you need extra energy to position the board. Over and over. And over...
And people report to ride the board for as long as you can to get in the air. I am the opposite.
I do not ride the board. Not for long anyway. It is quick movement with the legs, almost like slicing a bread, and off u go. It is that fast, the foil can lift you in that split second. Providing you are powered. If not powered, sure. But we only need power when starting. That tiny moment. And after that is irrelevant when learning. This is where bigger kite helps because it is slow. But needs a lot of depower on the bar, like 80cm or so.
Hope this helps.