Glad it worked out. I had exactly the same experience.
Mine also cracked with polycarbonate. I lost two of the three aluminium props. The weak spot is the relatively thin wall where the screw goes in. I’ve just printed a set with PET-CF to try and will then try PPA-CF. Ultimately though, I think we need to redesign the hub to have a slightly thicker wall where the screw goes in. I just haven’t had the time.
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Agree it needs thicker walls, I have a friend who is going to redesign the hub as he is also using it for foil assist and has better CAD skills than me. He did solve it in the short term though by melting a staple into the weak area 
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would you be able to send me the files for these props ?
A simple fix is to do it like Mantafoils and have it split at the base and screw on the three (now). failing pieces to the base.
That way you could print it in the right direction and there would be no more problems.
On the other hand, I have not had any failing.
Printed in PC with no cooling.
Any addition of CF will only weaken layer adhesion and make the problem worse.