I have been flying the other large non composite Boomerang with wire struts. They work great. What is nice is when you have a landing and go into a rough area you just bend the wire back. I have just finished the new XL. Spring air has an adapter to fit wire strut to retracts. I am using the robart 630 and wire struts.
If you are using the struts and on grass, I think you had better beef up the area well. So far at our field, the score is wire struts 0, struts 4 for tearing out the retracts.
Burt