I've used those little straps before and they're pretty hard to break, I had them on a Goldberg Cub. the main/front gear went into the gear blocks and the straps held the rear wire in place. When my radio went wacky and the plane hit the water those little straps were fine, they just didn't have very much plane left around them any more.

If you're nervous about them, why not try doubling them up or use them mains that came with the kit in the front and the wire in the rear. be sure and install spreader bars front and rear.

They should work fine unless you really have a hard landing/Crash
Then you'd probably rather have or the straps break or the screws pull out other than the whole bottom of the fuse come off?

Add water have fun