Mr. Cox,
YES, I am fairly sure about this (from all reports). Apparently it is not the high RPM running that strains the crank, rather it is hobbyists grinding on and more importantly the STARTING. Picco is too high a quality manufacturer of high performance engines to put out a crank that would not withstand running conditions. (They have world championship car engines) Fragile...perhaps, but fragile to tolerating flooded conditions while being mechanically spun over.
I recommend that you go ahead & run them. 30,000+ RPM is a unique sound to say the least! ENJOY!
Your Cox Venom however is an engine that WILL FAIL after less than a dozen runs without any abuse. But that is due to a flaw in the piston crown machining... (that's another story however).
Cheers, Paul