Conifers (juniper is a conifer, as is yew) form compression wood as reaction wood when a limb/trunk is growing at an angle. The lower side of the branch will form compression wood, while the upper side is under tension. However, tension wood forms in angiosperms (hardwoods) and not in conifers. The compression wood formed in the lower side of a juniper branch is very good in compression, better than wood from a straight trunk. I am not sure how compression wood will do when put under tension, as compared to 'normal' straight wood. But compression wood from the branch should do VERY well when it is sinew backed. Better than normal wood that is not reaction wood, according to the theory. So in my opinion, it is by no means undesirable and you will notice a better performance.
