I also use toggles made from arrow shafts but mine are a combination of CF and aluminum. From what i can see its like an aluminum tube wrapped in CF. I would think that they reinforce and so far they have worked very well for me and i am a bit on the heavy side.
This is why we have not gone the CF route. Ours our made from aluminum arrow shafts and nobody has reported a failure to date. My own personal toggles were made quite some time ago from a section of an Easton tent peg and they are still going strong.