Hi Jim,
I remember several years ago (around 12, more or less) that larger Dyna Thrust props were proported to have shed a blade in the air now and then. As I recall, the manufacture put out some info about the importance of balance, multi bolt prop hub prop drilling, and spinner clearance. I also recall hearing that the manufacture had reconstitued the material the props were made from although I don't remember his ever acknowledging any responsibility for a potentially faulty product.

I used a Dyna Thrust 22X10 on a Zenoah G-62 in a Sig 1/3 scale Space Walker, which I fly off the water on occasion. (extended Sig !/4 Scale floats). I used the prop for several years
with no problem in both ROG and ROW configurations. Last year, the prop finally shed a blade in flight, breaking off at about 2 inches out from the spinner. Fortunately, I recognized the change in sound and shut down the engine almost immediately and was able to glide in for a smooth middle of the runway landing. At first appoearance, the model looked ok...but in reality, the vibration had torn loose almost everything inside the fuse and the wing was ready to fall off. I was very fortunate to get the model back on the ground in repairable condition.

I must acknowledge that I had not inspected the prop for cuts, nicks or deep scratches that are possible as the result of flying from a dirt runway. After the fairly extensive repairs, I started using Zinger wooden props and found an improvement in thrust. I would suggest that you need to know the age of the DynaThrust props you have on hand and not risk there use if they are very old. Further, I beleive you'll bee happier with the greater efficiency of several manufacturers wooden props unless you are talking about flying of the water In any event, the near loss of my plane was a reminder of the importance of regularly inspecting any prop for cuts, nicks, cracks along the blades and taking the spinner off to check the apparent condition of the prop hub.

It is also worth while noting that Master Airscrew has discontinued the production of their larger "plastic'' props as the result of liability issue concerns following some reported failures.
I will be checking out the use of a carbon fiber prop for my water flying in the future.